Leveraging member-initiated online communities: the role of brand prominence, content authenticity and social capital

The rise of digital communication channels has accelerated the growth of online communities (Park et al., 2018). These communities are formed by individuals who share a common interest, interact through technology and operate under group-specific norms (Porter and Donthu, 2008). While marketing research has extensively examined brand communities, it has largely overlooked online communities that emerge organically around shared interests unrelated to any specific brand – what we refer to as member-initiated online communities (MIOCs) (Heehyoung et al., 2008). Examples of well-known MIOCs include r/gaming on Reddit and Cheap Meal Ideas on Facebook, each with millions of members. Reddit, the leading platform for such interest-based communities, now supports over 100,000 active groups and has experienced a 35% increase in these communities between 2023 and 2025 (Cropink, 2025; Reddit Business, 2025a). Brands advertising on Reddit are also 46% more likely to be trusted by users (Reddit Business, 2025b), underscoring the strategic relevance of MIOCs for companies. Indeed, brand-generated content on social media is a widely applied marketing technique by firms (Kumar et al., 2016) as it can create positive word of mouth (WOM) and virality, especially among well-connected users (Hinz et al., 2011), such as MIOC members. MIOCs, therefore, represent an attractive yet underleveraged marketing context, often viewed as a “new customer segment” (Kotler et al., 2017).

Despite this potential, marketing research has not fully addressed the commercialization potential of MIOCs (see Table 1). Existing studies have focused on members’ motivations (Bradford et al., 2017), their value generation (Agrawal and Ramachandran, 2017; Alhashem et al., 2021), participation intention (Becker et al., 2010; Thompson et al., 2016) or out-group participation in emotional support contexts (Johnson and Lowe, 2015). While Park et al. (2018) explore social ties and purchase behaviors in gaming communities, the role of brand-generated content in MIOCs remains largely unexamined representing a critical gap in the literature.

Addressing this gap, we investigate how brand-generated content performs in MIOCs – spaces where communication typically flows from members to members, not from brands to consumers. Our study builds on recent research calls to better understand how brands can engage in such organically formed communities (Alhashem et al., 2021; Park et al., 2018) and aims to contribute to a more nuanced view of brand participation in nonbrand-centered environments. Following these calls for research and because of the considerable potential online communities represent for brands (Agrawal and Ramachandran, 2017; Fiedler and Sarstedt, 2014), we aim to fill the research gap on leveraging MIOCs from a marketing perspective. Specifically, we explore how brand-generated posts in MIOCs influence members’ positive WOM – a central outcome in digital marketing, defined as the favorable exchange of product-related information between consumers (Akpinar and Berger, 2017). WOM is a powerful mechanism for influencing consumer decisions and driving consumer acquisition (Lisjak et al., 2021; Villanueva et al., 2008).

To understand how MIOC members respond to brand-generated content, we draw on the persuasion knowledge model (Friestad and Wright, 1994). This model posits that individuals develop knowledge about persuasion tactics and use this knowledge to interpret and evaluate marketing efforts (Friestad and Wright, 1994). From a persuasion knowledge perspective, some factors can increase or decrease consumers’ critical thinking about communication elements (Eisend and Tarrahi, 2022). In this regard, for online marketing initiatives, consumers interpret marketing cues to evaluate the initiatives (Eigenraam et al., 2021). For brand-generated content in MIOCs, the key marketing cue is the conspicuousness of the brand name or logo in the content, referred to as brand prominence (Han et al., 2010). Thus, we expect the content’s brand prominence to be an important antecedent influencing the effectiveness of brand-generated content in MIOCs.

We further propose perceived post authenticity – the extent to which content is seen as a genuine expression of the content creator’s thoughts and experiences (Beverland and Farrelly, 2010) – as the central mechanism through which brand prominence affects WOM. In peer-driven communities like MIOCs, authenticity is a particularly salient concern (Chiu et al., 2006), as members expect information to originate from peers rather than brands. By examining brand prominence of posts and perceived post authenticity, the present research also responds to the call for research on communication elements that influence persuasion knowledge activation (Eisend and Tarrahi, 2022).

In addition, we draw on social capital theory (Bourdieu, 1986), as social capital represents a key resource arising from group membership and is a defining characteristic of MIOCs (Lin and Lu, 2011; Putnam, 2000). Prior research has emphasized the importance of applying social capital theory to marketing (Van den Bulte et al., 2018), yet its role in shaping consumer responses to brand communication within peer-driven online communities remains underexplored. In our study, we investigate how social capital – reflected in the trust, reciprocity and shared norms embedded in member relationships (Coleman, 1988) – influences the effectiveness of brand-generated content in fostering positive WOM in MIOCs.

To examine this, we conduct a multi-method investigation comprising an exploratory pilot study, a field experiment and two online experiments. The pilot study uses a quasi-experimental design to assess how MIOC members perceive brand-generated posts in their community (see  Appendix 1 for details). Study 1, a field experiment conducted in collaboration with a European skincare startup, tests the effect of brand prominence on user engagement as measured by click-through rates (CTRs) – an established proxy for WOM (Zhang and Mao, 2016). Studies 2 and 3 extend this inquiry by examining how brand prominence and perceived post authenticity interact with social capital to influence positive WOM in controlled online experimental settings.

MIOCs constitute a distinctive online community context in which peer-to-peer interaction prevails over brand-led engagement. Unlike many social media platforms that are often characterized by fleeting interactions, MIOCs are built on sustained member relationships and high levels of social capital. This makes them a particularly relevant yet underexamined setting for studying how consumers respond to brand-generated content. By exploring this dynamic, our research offers several contributions to marketing theory and practice. First, and to the best of our knowledge, this study is the first to empirically investigate how brand-generated content affects positive WOM in MIOCs, with WOM representing the most influential means in shaping consumer behavior and purchase decisions (Lisjak et al., 2021). By doing so, we highlight the strategic potential of MIOCs as a marketing channel and illuminate how MIOC members respond to brand efforts to engage in these peer-based environments. Second, by manipulating the level of brand prominence in posts, our study provides insights that help reconcile prior conflicting findings on the effectiveness of overt versus subtle branding in online content, refining our understanding of how conspicuous brand cues function in MIOCs. Third, this study contributes to the literature on message design by deepening our understanding of how communication elements – specifically, perceived authenticity – act as key drivers of positive brand outcomes in digital contexts (Hu et al., 2020). Fourth, we further extend prior work on social capital, the core variable behind relationship building (Adler and Kwon, 2002), within the domain of marketing. Examining how social capital among MIOC members contributes to the creation of brand WOM, we investigate brand benefits stemming from social capital. Finally, our findings offer practical guidance to companies aiming to engage authentically in MIOCs, equipping them with actionable strategies for leveraging these communities as an effective marketing channel for fostering brand WOM.

Online communities have become central to how consumers interact, exchange knowledge and cocreate meaning in digital environments (Kotler et al., 2017). These communities vary widely in purpose and structure and are commonly categorized either as communities of interest – unrelated to a specific brand – or as brand communities (Porter, 2004) (see Figure 1). Online communities of interest, also referred to as MIOCs, are created by individuals who gather around shared values, interests or activities that are not tied to any particular brand (Heehyoung et al., 2008). These communities often focus on broader lifestyle themes (e.g. r/yoga on Reddit) or product categories (e.g. r/motorbikes on Reddit).

By contrast, brand communities are organized around a focal brand and comprise consumers who interact with one another and with brand-related content (Muniz and O’Guinn, 2001). Brand communities can be brand-hosted, such as the Harley Owners Group (individual website), the Nike Facebook page or the Reddit community r/lululemon. They can also be member-hosted, such as the Harley-Davidson Fans or Thermomix Tips and Recipes groups on Facebook, which, although independently operated, remain centered around a specific brand.

While member-hosted brand communities share certain features with MIOCs – particularly their organic emergence – they are still brand-centric and reflect the structured social dynamics typical of brand communities (Pedeliento et al., 2020; Veloutsou and Liao, 2023). At the same time, many MIOCs can be viewed as consumption communities that are structured around product categories rather than specific brands (Thompson et al., 2017). This distinction highlights the importance of understanding brand participation and consumer identification in communities that are not defined by brand affiliation.

MIOCs predominantly function as platforms for information exchange, facilitating a continuous flow of information among MIOC members (Park et al., 2018). A substantial amount of this information focuses on recommending products related to the shared topic of interest in the MIOCs. This information serves to heighten awareness (Pyo et al., 2023) and mitigate risks associated with new products, ultimately leading to an increased likelihood of product purchases (Huang, 2016). Individuals tend to disseminate information acquired from trustworthy sources (Leonhardt et al., 2020; Shen et al., 2016), such as other members of the MIOC, resulting in the generation of positive WOM. Nevertheless, research has yet to investigate whether MIOC members would be inclined to share the information acquired from commercial sources, such as content generated by brands.

The potential for generating positive WOM regarding brand-generated content within MIOCs arises when MIOC members perceive the information provided by commercial sources as valuable (Bruyn and Lilien, 2008). At the same time, brand content in MIOCs is potentially perceived as persuasive advertising content with promotional intent (Boerman et al., 2017), thereby triggering adverse coping responses among MIOC members due to the activation of persuasion knowledge (Eisend and Tarrahi, 2022). In this regard, brand prominence can activate persuasion knowledge (Choi et al., 2018; Tellis et al., 2019; Xiao et al., 2024).

Research has already attempted to identify the optimal level of brand prominence in online content, to avoid persuasion knowledge activation. Akpinar and Berger (2017) propose that stronger brand prominence increases electronic WOM for informational content while it reduces electronic WOM for emotional content. Aribarg and Schwartz (2020) examine brand prominence in native and display advertising and find that ads with higher brand prominence can lead to a higher CTR depending on the context. While examining video advertising, Davtyan et al. (2021) find that more prominent, but not excessive, brand placement is associated with positive WOM, as it initiates consumer discussions about the brand. On the contrary, Choi et al. (2018) and Tellis et al. (2019) find that high levels of brand prominence in online content can cause content avoidance and negatively affect positive WOM generation, as consumers’ persuasion knowledge becomes activated. Similarly, Xiao et al. (2024) demonstrate that lower brand prominence leads to higher social media engagement.

Despite these divergent findings and the apparent dependence of the brand prominence effect on additional factors, the literature generally tends to suggest that higher brand prominence of brand-generated online content works “against marketers’ goals” because of the resemblance of the content to an ad (Stephen et al., 2015). Building upon the notion of the persuasion knowledge model and considering the fundamental role of MIOCs as platforms of information exchange among private members, we expect that MIOC members will view higher levels of brand prominence of brand-generated content in MIOCs as a persuasion attempt, which is likely to trigger the activation of persuasion knowledge, consequently adversely affecting positive WOM generation by the MIOC members. Thus, we hypothesize:

Previous research highlights the crucial role of perceived authenticity of online brand activities on consumer-related responses (Eigenraam et al., 2021; Zhang and Patrick, 2021). Consumers tend to perceive brand-generated content as authentic when they believe that its creation is motivated intrinsically – resulting from the passion for the brand – and not extrinsically – based on profit objectives (Audrezet et al., 2020; Ertimur and Gilly, 2012). The brand’s motivations are related to branding cues included in the content (Beverland and Farrelly, 2010), such as the brand prominence of brand-generated content in MIOCs. For example, in the context of influencer marketing and direct or indirect brand mentions, Hu et al. (2020) find that indirect brand mentions lead to lower perceived authenticity because they signal hidden extrinsic motivations. Similarly, members potentially perceive brand-generated posts in MIOCs as a deceptive promotional tactic that is not intrinsically motivated and, thus, as unauthentic. Specifically, as the level of brand prominence and, consequently, the resemblance of the post to an ad increases (Boerman et al., 2015; Choi et al., 2018), we expect that posts will be perceived as less authentic.

Generally, higher perceived authenticity of brand-generated content leads to more favorable evaluations of the content (Orazi and Newton, 2018), increases the likelihood of information sharing and, if the content generator is a brand, even mitigates any negative brand impressions increasing users’ purchase intention (Hu et al., 2020; Zhang and Patrick, 2021). Previous studies have demonstrated the positive relationship between perceived post authenticity and WOM (Eigenraam et al., 2021; Zhang and Patrick, 2021). In the context of brand-generated posts in MIOCs, perceived post authenticity is likely to represent a key variable that mediates the relationship between brand prominence and WOM. Specifically, as brand prominence increases, we expect that the brand-generated post will be perceived as less authentic by MIOC members because such posts may activate their persuasion knowledge (Morhart et al., 2015), which in turn negatively affects positive WOM generation. Thus, we hypothesize:

What differentiates MIOCs from other social media contexts is that MIOCs are, by definition, groups of individuals sharing common interests (Porter and Donthu, 2008). Social capital refers to the actual and potential value arising from membership in a group that is embedded within the network of relationships created around the group (Bourdieu, 1986). According to Nahapiet and Ghoshal (1998), social capital is a three-dimensional construct comprising a structural dimension (i.e. ties between the group members and patterns of connections in the community), a relational dimension (i.e. trust between community members) and a cognitive dimension (i.e. shared values between the community members). Social capital is considered a durable asset, found on both the individual and collective levels in group membership (Krishen et al., 2019b; Mathwick et al., 2008), that can be translated into economic capital (Adler and Kwon, 2002). Social capital thus represents a critical resource in MIOCs (Mathwick et al., 2008) that brands could leverage. Building on the foundation of social capital theory, we posit that social capital, as a critical resource, influences members’ responses to brand-generated content in MIOCs. High social capital implies stronger ties, greater trust and shared values among MIOC members, fostering an ideal context for positive WOM generation.

Marketing literature has explored the effect of social capital on brand-related outcomes. For example, Van den Bulte et al. (2018) find that companies can capitalize on the social capital between consumers through referral programs to generate higher margins. In comparing the effectiveness of Facebook advertising and brand communities, Chi (2011) shows that consumers respond more favorably to brand-generated content in brand communities because of the preexisting social capital. In the context of MIOCs, social capital facilitates information diffusion and new product adoption because members with high social capital with their MIOC are motivated to exchange information and potentially adopt other members’ consumption behaviors (Pyo et al., 2023). In high social-capital settings, such as MIOCs, information shared among the individuals is often perceived through a lens of homophily (shared values and beliefs) and credibility, as observed in related research on text-based electronic WOM (Onofrei et al., 2022).

Building on these findings, we posit that social capital should also play a vital role in understanding the effectiveness of brand-generated content in MIOCs. In the context of advertising, attitude toward an ad is improved when it is received from a close social tie (i.e. structural dimension of social capital) (Shen et al., 2016). In the context of social networks, users exhibiting high social capital are more likely to generate WOM regardless of the content’s credibility (Gvili and Levy, 2018). Based on these findings, we expect the community’s ties, trust and shared values to override skepticism toward brand-generated content, attenuating persuasion knowledge through the perceived authenticity mechanism. Specifically, we expect that MIOC members’ high social capital weakens the hypothesized effect of perceived post authenticity on members’ motivation to spread positive WOM about the brand because persuasion knowledge is less likely to be activated, due to the social capital of the MIOC members with their MIOC. Thus, we hypothesize:

Figure 2 summarizes our research model, and Figure 3 provides an overview of the studies exploring this model.

In Study 1, we explore the effect of brand prominence on brand-related outcomes (H₁) using a controlled field experiment on Reddit MIOCs. To assess the effect of brand-generated posts in MIOCs in a real-life setting, we cooperated with the European skincare startup EIGENHAIN.

Together with the skincare startup, we designed a between-subjects online field experiment. We used one of the company’s skincare products as the stimulus in this experiment and designed two posts with varying levels of brand prominence, namely, high or low, for Reddit skincare and beauty MIOCs. We aligned the posts with the focal MIOCs’ thematic focus to fit their norms and post type (Kozinets et al., 2010). The posts consisted of a title, a visual and text (see Figure 4). In the high-brand-prominence condition, the title mentioned the brand name, and the visual included a photo of the product with the brand name on both the packaging and in a separate text above the photo. The text mentioned the brand name multiple times. In the low-brand-prominence condition, the title did not mention the brand name, and the visual included a photo of the product with the brand name on the packaging only; the following text mentioned the brand name only once. Each post was visible to the members of one of two similar (in terms of size, daily number of posts and average upvotes) Reddit skincare and beauty MIOCs. The posts were marked as “promoted.”

Most Reddit posts are short-lived, with a lifetime of a few hours (Haralabopoulos et al., 2015). However, we let five days pass before we measured the overall number of post views and the clicks generated for each post. The number of clicks relative to the number of views is a crucial metric for marketing experts (Aribarg and Schwartz, 2020) and can be converted into online sales (Dinner et al., 2014) and positive WOM (Zhang and Mao, 2016). As the number of clicks increases, the consumer evaluation of the featured product improves, positively influencing the intention to spread WOM (Zhang and Mao, 2016). In this field experiment we, thus, explore an important precursor for WOM generated in MIOCs.

We compared the similarity between the two MIOCs selected to create the posts. While we could not control the number of views a post would receive, as this depended on the social media platform algorithm, we measured the MIOC size, daily number of posts and the average upvote rate as a measure of how many members approved of the post’s content and compared them between the MIOCs. On the day of posting, the Reddit MIOC used for the low-brand-prominence post had 1.5 million members, 35 posts and an average upvote rate of 9.49. The Reddit MIOC used for the high-brand-prominence post also had 1.5 million members, 31 posts and an average upvote rate of 10.74. A chi-square test of the difference between the two MIOCs for the number of posts and the upvotes showed no significant differences between the MIOCs for both control metrics (χ²_{number of posts} (1, N = 3 million) = 0.24, p = 0.62; χ²_{number of upvotes} (1, N = 3 million) = 0.05, p = 0.83). Thus, the two MIOCs were comparable.

Five days after the posting, we counted the total number of MIOC member reactions to the two experimental posts. The low-brand-prominence post was viewed by 11,876 members in this five-day period, while the high-brand-prominence post was viewed by 18,926 members. However, the low-brand-prominence post received 35 clicks (CTR = 0.3%), while the high-brand-prominence post received only 29 clicks (CTR = 0.15%). While these CTRs seem low, the CTRs for both posts were higher than the average display ad CTR, which is 0.1% (Aribarg and Schwartz, 2020). We used a chi-square test of difference to assess the effect of the low- and high-brand-prominence post on the overall number of views and the clicks generated. The results show that the chi-square difference between the clicks generated was significant [χ² (1, 30,802) = 7.05, p = 0.008] and lower for the high-brand-prominence condition, providing support for H₁.

The results of Study 1 suggest that posts with lower levels of brand prominence can lead to more favorable brand-related outcomes in terms of clicks generated for products posted in MIOCs. While CTRs are not a direct measure of WOM, they provide an important behavioral indicator of consumer engagement with the content. Previous studies have demonstrated that clicks is a necessary precursor to WOM activities, such as retweets and shares, particularly in networked environments (Oh et al., 2016). Furthermore, CTRs are widely used in the marketing literature as proxies for consumer interest, persuasion and even value generation (Cian et al., 2020; Villanueva et al., 2008). Other studies show that generated clicks is an important driver of WOM (Zhang and Mao, 2016). Our findings align with these studies and point to an intriguing opportunity for brands intending to leverage MIOCs, suggesting that lower brand prominence increases CTRs and, by extension, may foster greater WOM potential in MIOCs. Furthermore, the high CTRs achieved indicate that MIOCs can serve as part of an omnichannel marketing strategy if executed carefully.

To better understand members’ perceptions of brand-generated posts in MIOCs, we conducted an online experiment using the stimuli created for our field experiment in Study 1, to discern situations in which brand prominence was absent, low or high. We investigated the mediating role of perceived post authenticity in the relationship between brand prominence and WOM, testing H₂, and the moderating role of members’ social capital with their MIOC to explore the effect of social capital on the impact of brand-generated posts in MIOCs, testing H₃ (see Figure 3).

We recruited study participants via the Prolific panel to take part in a between-subjects online experiment. To ensure that participants were active members of a skincare and beauty MIOC on Reddit, we asked them about their last MIOC visit and the internet link to their MIOC. From the collected active MIOC member responses, we removed participants from the sample who failed the attention check or speeded through the questionnaire, resulting in a total sample of 221 active Reddit skincare and beauty MIOC members (M_age = 26.4 years, 46% female) for our study.

Participants first answered a series of research questions about their MIOC use (i.e. visit frequency, active participation frequency and length of membership). We then randomly assigned them to one of three experimental conditions, no brand prominence, low brand prominence and high brand prominence. Across all conditions, we asked participants to imagine scrolling through their MIOC website and coming across a post about a skincare product, representing a thematic fit with MIOC’s focus. All participants then saw a screenshot of the post. In the low- and high-brand-prominence conditions, participants received a screenshot of a post created by a brand selling skincare products. In the no-brand-prominence condition, participants saw a post created by a community member. For the low- and high-brand-prominence conditions, we used the same stimuli as in Study 1. In the no-brand-prominence condition, the post included an unbranded sketch of a skincare product packaging and no brand mentions (see Figure 4).

After participants viewed the post, we explored their reactions to perceived post authenticity (Hu et al., 2020; Zhang and Patrick, 2021) and WOM (Eisingerich et al., 2015; Lisjak et al., 2021), which we measured by adapting established scales. For perceived post authenticity, participants indicated on a seven-point Likert scale their agreement with the following statements: “The post is genuine and sincere,” “The post seems original,” “The post does not appear to be an advertisement” and “The post is authentic” (Cronbach’s α = 0.83). For WOM, we assessed their agreement to the following statements: “I would encourage friends and relatives to use the brand/product mentioned in the post,” “I would say positive things about the brand/product mentioned in the post to others,” “I would recommend the brand/product mentioned in the post to others” and “I would talk positively about the brand/product mentioned in the post to others” (Cronbach’s α = 0.93). In addition, we measured social capital as a three-dimensional construct using adapted scales from prior research (Bart et al., 2005; Jeong et al., 2021; Lin and Lu, 2011; Maxham and Netemeyer, 2003) (Cronbach’s α = 0.83). As a manipulation check, we included the item “Thinking back to the post described previously, how often was the brand mentioned in the post?” The participants could choose to respond “never” (1), “once or twice” (2) or “multiple times” (3). Finally, we assessed the key demographic information. For all constructs measured with multiple items (e.g. post authenticity, WOM), we ensured validity and reliability by calculating and reporting Cronbach’s alpha, composite reliability and average variance extracted (see  Appendix 2). These steps ensured that the constructs were conceptually robust and internally consistent.

We tested the mean values of participants’ perception of brand prominence in the different scenarios using a one-factor analysis of variance (ANOVA). The means differed significantly [M_{no_brandprominence} = 1.32 vs M_{low_brandprominence} = 2.16 vs M_{high_brandprominence} = 2.67; F (2, 218) = 141.16, p < 0.001]. Thus, our experimental manipulation was successful.

Applying linear regression, we found a negative, significant direct effect of brand prominence on WOM (b = −0.32, p = 0.004), as hypothesized in H1. This result remained significant after we included the control variables (i.e. visit frequency, active participation frequency, length of membership, gender and age). We further tested the effect of brand prominence on WOM using a one-factor ANOVA with brand prominence as the independent variable and WOM as the dependent variable. The results showed a significant decrease of WOM as brand prominence increased [M_{WOM_no_brandprominence} = 4.33 vs M_{WOM_low_brandprominence} = 3.88 vs M _{WOM_high_brandprominence} = 3.69; F (2, 218) = 4.55, p = 0.01], providing further support for H1.

Next, we assessed the persuasion knowledge mechanism reflected in the mediating role of perceived authenticity in the relationship between brand prominence and WOM. Treating brand prominence as a multicategorical variable (X1: none vs low; X2: none vs high), we ran a mediation analysis (Hayes, 2017, Model 4, 5,000 bootstrapped samples). To analyze the relationships between constructs, we used PROCESS modeling. This approach is particularly suited for exploring the conditional effects of moderators (e.g. levels of prominence), providing granular insights into the dynamics of these relationships. The results revealed that perceived post authenticity mediated the relationship between brand prominence and WOM (indirect X1 = 0.42, SE = 0.16, 95% CI = [−0.73, −0.12]; indirect X2 = −0.57, SE = 0.14, 95% CI = [−0.88, −0.31]). The direct effect of brand prominence on WOM became nonsignificant after we included perceived authenticity as a mediator, indicating full mediation and supporting H2.

Our findings demonstrate that MIOC members process and assess posts in their MIOC, as proposed by the persuasion knowledge mechanism. However, despite the negative effect of brand prominence on WOM, it is worth mentioning that WOM is above the scale-midpoint across conditions, proving that MIOCs can become a relevant and influential marketing channel. The relationship between brand-generated post and WOM is fully mediated by perceived post authenticity, which decreases when brand prominence increases. Perceived authenticity has a positive effect on WOM, suggesting that posts that are considered more authentic are more likely to generate discussions and product suggestions from MIOC members to their social circle.

Finally, we applied a moderated mediation model to explore whether social capital moderates the mediation through perceived authenticity between brand prominence and WOM (Hayes, 2017, Model 14, 5,000 bootstrapped samples; independent variable = brand prominence, mediator = perceived post authenticity, dependent variable = WOM, moderator = social capital moderating the relationship between the mediator and the dependent variable). Table 2 shows the detailed breakdown of the analyses.

The results revealed that the interaction between perceived authenticity and social capital had a significant, negative effect on WOM (b = −0.13, t = −2.11, p = 0.04). Social capital marginally moderated the indirect effect of perceived authenticity on brand WOM for X1 and moderated the indirect effect for X2 (index of moderated mediation X1 = 0.08, SE = 0.05, 95% CI = [0.00, 0.21]; index of moderated mediation X2 = 0.11, SE = 0.06, 95% CI = [0.01, 0.25]). Thus, WOM induced by the mediation model varies significantly depending on members’ social capital with the MIOC. The higher the social capital, the weaker the conditional effect of the mediation model.

To better understand the impact of social capital on the relationship between brand prominence and perceived authenticity, we conducted a floodlight analysis to show the effect and identify if and on which levels of social capital the indirect effect of brand prominence on WOM became nonsignificant (Spiller et al., 2013). As social capital increased, the indirect effect became weaker until it eventually became nonsignificant for members with high social capital with their MIOC (see floodlight analysis; Figure 5, Pane A), and brand WOM was high for all three conditions. These results provide support for H₃. Intriguingly, we found a positive direct effect of social capital on brand WOM (b₂ = 0.88, t = 3.42, p < 0.001), highlighting the important role of social capital in the MIOC context.

Study 3 serves to test and validate our complete research model in a different context. This experimental setting uses data from food- and fitness-related MIOCs on Facebook (see Figure 3). Thus, Study 3 uses a different MIOC context, a different product and a different platform.

We recruited active Facebook food and fitness MIOC members from the Prolific panel. We removed participants who failed the attention check or speeded through the questionnaire. Our final sample consisted of 152 MIOC members (M_age = 27 years, 52% female) who participated in a between-subjects online experiment with three experimental conditions: no brand prominence, low brand prominence and high brand prominence. We used a food sauce as the stimulus in this experiment to align with the MIOCs’ thematic focus.

In the high- and low-brand-prominence conditions, we exposed participants to a post created by “Tasty Sauce,” a fictitious brand selling low-calorie food sauces. In the no-brand-prominence condition, we told participants that they came across a post created by a community member. In the high-brand-prominence condition, the post included a picture of a meal prepared with the advertised sauce and a picture of the sauce, and the Tasty Sauce brand name was also mentioned multiple times. In the low-brand-prominence condition, the post included just a meal picture, and the text mentioned the brand name only once. Finally, in the no-brand-prominence condition, the post included the name of the community member, the meal picture and no brand mentions (see Figure 6).

We used the same measures as in our previous study for perceived authenticity (Hu et al., 2020; Zhang and Patrick, 2021) (Cronbach’s α = 0.82), WOM (Eisingerich et al., 2015; Lisjak et al., 2021) (Cronbach’s α = 0.94) and social capital (Bart et al., 2005; Jeong et al., 2021; Lin and Lu, 2011; Maxham and Netemeyer, 2003) (Cronbach’s α = 0.87) (see  Appendix 2 for an overview of the descriptive statistics and reliability and validity measures). As a manipulation check, we included the item “Thinking back to the post described earlier, how often was the Tasty Sauce brand mentioned in the post (in picture and text)?” The participants could choose to respond “never” (1), “once or twice” (2) or “multiple times” (3). Finally, we assessed scenario realism, participant involvement and key demographic information.

The participants evaluated the scenarios as highly realistic (M = 5.74, SD = 1.24; “How much do you agree with the following statement: I can imagine that situations similar to the one described exist”; 1 = “totally disagree” and 7 = “totally agree”) and felt involved in the situation (M = 4.58, SD = 1.61; “How much do you agree with the following statement: I felt involved in the situation”; 1 = “totally disagree” and 7 = “totally agree”). We tested the mean values of participants’ perception of brand prominence in their designated scenario by conducting a one-factor ANOVA. The means differ significantly [M_{no_brandprominence} = 1.23 vs M_{low_brandprominence} = 2.42 vs M_{high_brandprominence} = 2.68; F(2, 149) = 122.83, p < 0.001], indicating the effectiveness of our experimental manipulation.

We conducted a linear regression and found a significant, negative effect of brand prominence on WOM (b = −0.37, p = 0.006). The result remained significant after we included the control variables. As in the previous studies, we further tested the effect of brand prominence on WOM using a one-factor ANOVA with brand prominence as the independent variable and WOM as the dependent variable. We observed significant differences [M_{WOM_no_brandprominence} = 4.88 vs M_{WOM_low_brandprominence} = 4.54 vs M_{WOM_high_brandprominence} = 4.14; F(2, 149) = 3.82, p = 0.02]. These results provide further support for H₁ that an increasing level of brand prominence reduces WOM generated by MIOC members.

To test whether the perception of post authenticity mediated the relationship between brand prominence and WOM, we conducted a mediation analysis, treating brand prominence as a multicategorical variable (Hayes, 2017, Model 4, 5,000 bootstrapped samples, X1: none vs low; X2: none vs high). The results replicated those of Study 1 and Study 3, showing that increased brand prominence led to lower perceived post authenticity (b_X1 = −0.72, t = −2.64, p = 0.01; b_X2 = −1.31, t = −4.82, p < 0.001) and perceived post authenticity had a positive effect on WOM (b = 0.49, t = 6.09, p < 0.001). This resulted in a negative indirect effect of brand prominence on WOM (indirect X1 = –0.35, SE = 0.15, 95% CI = [−0.68, −0.08]; indirect X2 = −0.65, SE = 0.18, 95% CI = [−1.02, −0.33]), providing support for H₂. The direct effect of brand prominence on WOM became nonsignificant after we included perceived authenticity in the model.

We ran the moderated mediation model used in Study 2 to validate the moderating effect of social capital on the relationship between brand prominence and WOM (Hayes, 2017, Model 14, 5,000 bootstrapped samples; independent variable = brand prominence, mediator = perceived post authenticity, dependent variable = WOM, moderator = social capital moderating the relationship between the mediator and the dependent variable). Again, the effect of perceived authenticity on WOM was contingent on the MIOC members’ social capital with their MIOC (index of moderated mediation X1 = 0.09, SE = 0.05, 95% CI = [0.00, 0.21]; index of moderated mediation X2 = 0.16, SE = 0.08, 95% CI = [0.01, 0.33]). The indirect effect of perceived authenticity on WOM for both X1 (indirect X1_{low Soc.Cap.} = −0.35, SE = 0.16, 95% CI = [−0.68, −0.08]; indirect X1_{medium Soc.Cap.} = −0.26, SE = 0.12, 95% CI = [−0.53, −0.06]; indirect X1_{high Soc.Cap.} = −0.17, SE = 0.11, 95% CI = [−0.41, −0.01]) and X2 (indirect X2_{low Soc.Cap.} = −0.64, SE = 0.18, 95% CI = [−1.03, −0.31]; indirect X2_{medium Soc.Cap.} = −0.48, SE = 0.15, 95% CI = [−0.80, −0.22]; indirect X2_{high Soc.Cap.} = −0.32, SE = 0.16, 95% CI = [−0.66, −0.05]) showed that the effect was stronger among participants with low social capital, providing support for H₃. A floodlight analysis of the indirect effect of perceived authenticity on WOM for both X1 and X2 demonstrated that the effect is stronger among participants with low social capital. Specifically, we found that up to a social capital of 5.63, the indirect effect of perceived authenticity was significant (see Figure 5, Pane B). Finally, as in Study 2, we again observed a positive direct effect of social capital on WOM (b₂ = 0.89, t = 4.24, p < 0.001).

Study 3 replicates and validates the results of the previous studies in a different product and MIOC context. Overall, our findings show that brands can post brand-generated content in MIOCs to favorably influence the WOM generation. Importantly, we find that a low level of brand prominence generates more positive WOM. Perceived post authenticity fully mediates the relationship between brand prominence and WOM. Posts high in brand prominence result in a lower perception of post authenticity than posts with low or no brand prominence, a finding in line with the persuasion knowledge mechanism. Our findings again underscore the role of MIOC members’ social capital. Not only does social capital directly affect WOM, but also as social capital increases, the indirect effect of brand prominence on WOM mediated by perceived authenticity becomes weaker.

MIOCs serve as digital spaces where members can exchange information and form relationships around a common topic of interest (Bagozzi and Dholakia, 2002; Park et al., 2018). The relevance of MIOCs has increased with the ubiquity of social media and because of their potential to cultivate consumer opinions (Dholakia et al., 2004). In our study, we demonstrate the potential of MIOCs as an alternative marketing channel and shed light on the benefits of a brand entering an MIOC with the intention of generating positive WOM.

Our research shows that MIOC members respond positively to brand-generated content when it aligns with the community’s focus (Bruyn and Lilien, 2008; Kozinets et al., 2010). Building on initial exploratory insights from a pilot study, Study 1 – a field experiment – demonstrates that posts with lower brand prominence generate higher CTR, serving as a behavioral proxy for WOM (Cian et al., 2020; Zhang and Mao, 2016). To uncover the underlying mechanism shaping members’ responses, Studies 2 and 3 show that lower brand prominence enhances perceived content authenticity, which in turn fosters positive WOM. These studies also identify the moderating role of members’ social capital within their MIOC: as members’ social capital increases, the influence of perceived authenticity on WOM diminishes and ultimately becomes negligible at very high levels. Together, these findings contribute to the growing literature on MIOCs and offer actionable guidance for managers aiming to engage with these peer-driven communities.

Our study offers several important contributions to the literature. First, the potential of MIOCs as an untapped target for brands’ online marketing activities has so far remained underexplored (Kotler et al., 2017). Following prominent calls for research in this area (Park et al., 2018), we address this research gap and show that companies can elicit positive consumer reactions when posting brand-generated content in MIOCs, focusing on positive WOM as one of the most important metrics in online marketing (Lisjak et al., 2021). Intriguingly, our research reveals that brand-generated content in MIOCs, where the flow of information is typically from members to other members (Chiu et al., 2006), can significantly and positively impact the WOM generation.

Second, we contribute to prior research on the role of brand prominence in marketing content, within the context of MIOCs. We explore different levels of brand prominence of brand-generated content in MIOCs and identify a lower level of brand prominence in brand-generated posts as more effective for inducing positive WOM than posts where brands are highly prominent. Contributing to the limited body of research concerning communication elements that influence persuasion knowledge (Eisend and Tarrahi, 2022), and addressing the inconclusive results regarding the role of brand prominence in prior research (Akpinar and Berger, 2017; Tellis et al., 2019), our study demonstrates that posts high in brand prominence can trigger persuasion knowledge. This activation of persuasion knowledge negatively impacts members’ WOM, as compared to posts where the brand is featured less prominently.

Third, we identify the perceived post authenticity by MIOC members as an important mechanism explaining the effectiveness of brand-related posts with varying levels of brand prominence in generating positive WOM. In doing so, our research contributes to the literature on the importance of authenticity in online content (Eigenraam et al., 2021; Zhang and Patrick, 2021) and sheds light on MIOC members’ perception of promotional tactics by identifying perceived post authenticity as an important factor in persuasion knowledge activation (Eisend and Tarrahi, 2022). We demonstrate that perceived post authenticity fully mediates the relationship between brand prominence and WOM. As brand prominence increases, perceived authenticity decreases because the multiple mentions of the brand in the post result in ad resemblance (Boerman et al., 2015; Choi et al., 2018). For MIOC members, greater ad resemblance is likely to signal that the brand is predominantly extrinsically motivated, aiming to obtain higher profits, rather than being intrinsically motivated, providing a product from which members could genuinely benefit (Audrezet et al., 2020). Thus, our research reveals that high brand prominence due to multiple brand mentions in online posts works against companies’ interests in generating WOM because of downside effects on members’ perceptions of the post’s authenticity.

Fourth, we answer calls to investigate the role of social capital in online communities from a marketing perspective (Van den Bulte et al., 2018) and demonstrate that the social capital of MIOC members represents an essential moderating variable that influences the relationship between perceived post authenticity and WOM. The influence of the persuasion knowledge mechanism weakens until it becomes insignificant for MIOC members with high levels of social capital. This finding suggests that, in the MIOC context, the impact of social capital becomes so strong that it effectively nullifies the mechanism proposed by the persuasion knowledge model for members with high social capital. This integration extends existing knowledge by demonstrating that social capital can override the typically negative effects of activated persuasion knowledge, a relationship not previously explored in such depth. Communities whose members exhibit high social capital typically feature strong ties, trust and shared values among their members (Lin, 1999; Mathwick et al., 2008), which can yield a strong social influence (Park et al., 2018). Our study reveals that these social dynamics can not only mitigate skepticism toward brand-generated content but also facilitate positive WOM generation even for posts perceived as less authentic. By uncovering the dual role of social capital – as both a moderator of persuasion knowledge effects and a direct driver of WOM – this research offers novel insights into the interplay of social influence mechanisms and extends the theoretical boundaries of social capital and persuasion knowledge models in the context of MIOCs.

Finally, digital innovations have heightened the need to understand how consumer engagement is initiated, sustained and shaped across different forms of brand communication (Bowden and Mirzaei, 2021). Although our study focuses on MIOCs, the underlying mechanisms we identify – particularly the roles of social capital and persuasion knowledge – are likely relevant across other types of communities, including brand-hosted and member-hosted brand communities. These dynamics may also extend to broader social media contexts, where peer-based interactions, moderated by social capital, and perceptions of authenticity, shaped by persuasion knowledge, influence consumer responses to brand-generated content. In this way, our findings contribute to a more comprehensive understanding of digital content management and engagement strategies across a wide range of digital environments.

Our findings illustrate the promising marketing potential of MIOCs and provide guidance to online marketing managers on how to target these new segments effectively with brand-generated content. In our study, we demonstrate that MIOC members are generally receptive to brand-generated content, and thus, managers can leverage MIOCs as part of their omnichannel marketing strategy to generate positive WOM.

When targeting MIOCs with online marketing activities, we suggest that managers adopt a low level of brand prominence in posts. Lower brand prominence is less likely to induce persuasion knowledge processes that can negatively affect brand-related outcomes. Instead, lower brand prominence helps signal a brand’s intrinsic motivation to support and inform MIOC members, leading to higher perceived authenticity and, consequently, more WOM.

Our results also highlight the crucial role of perceived post authenticity. Studies 2 and 3 show that perceived authenticity fully mediates the relationship between posts’ commercial content and WOM. Thus, consumers in general and MIOC members in particular seem to value authentic brand content when generating WOM. One way for managers to achieve authentic brand content is through lower brand prominence because then, the content’s ad resemblance decreases. Other factors influencing the brand content’s authenticity include the accuracy, connectedness and originality of the marketing claims embedded in the content (Nunes et al., 2021), which managers should also consider for brand-related posts in MIOCs.

Finally, our findings reveal potential brand benefits due to the social capital of the community members, revealing the power of trust and social ties. Managers should target their marketing strategies at well-connected consumers, as represented by the MIOCs, while paying attention to the thematic focus of the MIOC and the content design. First, the thematic focus should be on the company’s product offering, and second, the brand-generated content should follow the type of content usually posted in the MIOC (Kozinets et al., 2010). One way to leverage social capital further is to form MIOC subgroups consisting of members who are strongly attracted to specific products and brands.

Our study has several limitations that open windows of opportunity for future research. First, we focus on the MIOC context. Future research could compare whether the relationships and effects discussed in this research hold in other contexts, such as social media or platforms.

Second, our study focuses on brand prominence as the primary independent variable. While this focus aligns with the study’s aim of exploring how brand-generated content can foster positive brand outcomes, future research could examine additional dimensions of brand-related posts, such as thematic fit with the MIOC’s focal interest, narrative style, tone or emotionality (Kozinets et al., 2010; Seraj, 2012). These elements may be critical in shaping MIOC members’ reactions to brand-generated content.

Third, our study investigates positive WOM as the central outcome variable, representing a key construct widely relevant in the digital marketing literature. However, brand participation in MIOCs could also lead to negative outcomes, such as negative WOM, skepticism or community backlash. Future research should expand the range of dependent variables to capture these potential adverse effects and explore the conditions under which these outcomes are more likely to occur. Such research could offer a more comprehensive understanding of the dual-edged nature of brand participation in MIOCs, helping to balance potential benefits against associated risks.

Moreover, social capital is a construct that, due to its nature, is difficult to grasp analytically. We used the three-dimensional conceptualization of Nahapiet and Ghoshal (1998). However, alternative conceptualizations include the bridging and bonding nature of social capital (Williams, 2006). Future research could examine whether our findings hold with conceptualizations capturing different aspects of social capital. Such research would be particularly valuable, as we find that social capital plays an important role in the effectiveness of brand-related posts in MIOCs.

Further, our study focuses on the effectiveness of brand-related posts in generating WOM in MIOCs of interest related to food, fitness and beauty themes. While these MIOCs represent a large proportion of existing MIOCs and widely appear across social media platforms, future research could investigate MIOCs with different thematic foci, such as goal-oriented communities of interest, learners’ communities and communities of practice (Henri and Pudelko, 2003) to complement our insights into the promising opportunity of MIOCs for brands. For instance, communities of practice (e.g. professional groups like engineers or medical practitioners) are characterized by deep expertise and shared professional values. In such settings, the credibility and technical relevance of brand-generated posts might be critical for eliciting positive responses.

Finally, our study was conducted using startups or fictitious brands in our experiments. While this approach ensures control over prior brand associations, it may limit generalizability to scenarios involving well-known brands. For instance, high social-capital members could exhibit a different reaction when exposed to branded content from an established or polarizing brand. In such cases, a backlash against overtly brand-generated posts may occur, as members’ existing knowledge of the brand’s products or attachment to the brand might influence their perceptions and interactions. Future research should examine whether the effects observed here extend to well-known brands or products.

To gain initial insights into how members of MIOCs respond to brand-generated posts, we conducted an exploratory pilot study in the form of an online quasi-experiment using Amazon Mechanical Turk. We recruited participants who were active members of at least one MIOC at the time of the study. The final sample comprised 237 participants (30% female; M_age = 35).

Participants first answered general questions about their MIOC usage, including visit frequency, level of active participation and satisfaction. They were then randomly assigned to one of two experimental scenarios. In both scenarios, participants were asked to imagine scrolling through posts in their MIOC and encountering a post, including a product recommendation. In the user-generated condition, the post was described as having been created by another community member. In the brand-generated condition, it was described as having been posted by a brand. Participants were then asked: “Thinking of the situation described above, what is your opinion about it?”

Responses to the user-generated post were consistently positive. For instance, one participant remarked: “It is very helpful that this member suggested a product related to the area of interest. I frequently look for new and improved products, so any suggestion is helpful to me.” By contrast, reactions to the brand-generated post were more nuanced. Some participants expressed openness to brand posts when the product aligned with their interests: “I would be interested in buying the product if it matches my need and interest.” Others emphasized the importance of authenticity and tone: “I generally do not like advertisements, but if it is done organically and in a way that improves the community, instead of exploiting it, then it is perfectly fine.” Finally, some participants reacted negatively, framing the post as intrusive advertising: “I do not think companies should be allowed to advertise directly in groups like this.”

These findings provide initial evidence that brand-generated posts in MIOCs can elicit positive responses – provided they are perceived as authentic and aligned with the community’s norms and interests. At the same time, the mixed reactions highlight the need for a more systematic investigation into how such content should be crafted to foster favorable outcomes.