Brand advocacy: a scoping review and future research agenda Open Access

Brand advocacy refers to the proactive and voluntary actions taken by consumers to promote and endorse a brand to others, typically through positive word-of-mouth (WOM), social media posts and other forms of brand advocacy, stemming from their loyalty, satisfaction, commitment and attachment to the brand (Keller, 2007; Wallace et al., 2012; Bhati and Verma, 2020). Brand advocacy is considered one of the key constructs in consumer–brand relationship research (Wallace et al., 2012; Keller, 2007). As the market grows increasingly competitive, consumers face an abundance of choices in the marketplace, and traditional advertising has less influence on their purchase decisions (Petro, 2024); thus, brands have shifted their focus to promoting consumer-to-consumer interactions (Cornell, 2024; Geyser, 2024). In particular, compared to company-generated advertising messages, recommendations from other consumers are often considered more credible and trustworthy (López and Sicilia, 2014). Brand advocacy, which involves one consumer advocating for a brand in communications with other consumers, has become a powerful phenomenon in the consumer landscape and serves as a mutually beneficial force for companies and consumers (Wilk et al., 2021; Bhati and Verma, 2020).

Brand advocacy is an opportunity for companies to increase brand visibility, credibility and profitability. When consumers become brand advocates, they become unpaid marketing agents, spreading positive WOM and endorsements that advertisement expenditures cannot generate (Keller, 2007; Keller and Fay, 2012). This organic promotion attracts new customers, fosters loyalty among existing ones and increases sales and market share. By advocating for brands they love, consumers become part of a community, establishing a sense of belonging and loyalty (Coelho et al., 2019; Wong and Hung, 2023). Their voices are also amplified in the marketplace, influencing other consumers’ purchasing decisions and ensuring that companies deliver products and services that meet their needs and expectations. In sum, brand advocacy creates a symbiotic relationship in which companies and consumers thrive in a mutually beneficial ecosystem.

Marketing scholars have examined brand advocacy from consumers’ cognitive and affective perspectives and within the context of brand community engagement and behavioural intentions (Wilk et al., 2021; Jayasimha et al., 2017). The current corpus of literature also illustrates a wide array of research focusing on the impact of brand advocacy on consumer–brand relationships. Although brand advocacy has become a key construct in relationship marketing, the stream of research is still fragmented (Bhati and Verma, 2020). Moreover, consumer behaviour has gone through a series of shifts over the past decade because of the proliferation of social media, an influx of online sales platforms and the recent advancement of the metaverse and artificial intelligence (AI). These developments have not only transformed the landscape of brand advocacy research but also introduced new opportunities and challenges for marketing practitioners. In light of these developments, this review paper aims to identify and evaluate potential avenues of future research on brand advocacy to advance the construct in the marketing literature and to provide insights for practitioners.

To achieve this goal, this paper undertakes a scoping review of the relevant literature, which is imperative to understanding the current state of research and providing directions for future research. This review fills a gap in the extant branding literature by thoroughly examining brand advocacy. To the best of the authors’ knowledge, there has been no scoping review of the construct to date. While this review acknowledges Bhati and Verma’s (2020) meta-analysis of brand advocacy antecedents, their study was limited to quantifying effect sizes within a narrower set of variables. In contrast, this scoping review adopts a broader perspective, synthesising diverse theoretical frameworks, methodological approaches and contextual applications, as well as mediators, moderators and outcomes. By mapping the full landscape of brand advocacy research, this review not only builds on prior efforts but also sets distinct objectives aimed at advancing conceptual and practical understanding in the field. This review makes significant contributions to the brand advocacy literature. Theoretically, it establishes clear conceptual boundaries between brand advocacy and related constructs (e.g. brand loyalty and WOM) by synthesising diverse research streams into a cohesive framework. Practically, it provides marketers with an integrated understanding of the antecedents and outcomes of brand advocacy across diverse contexts and provides insights for developing more effective advocacy-building strategies in an increasingly complex marketplace. The systematic analysis of methodological approaches in this review advances the field by identifying critical measurement gaps and proposing standardised scales for future research.

The remainder of this review paper is organised as follows: First, the conceptual definition of brand advocacy is discussed (Section 2). Next, the methodology of the review is outlined (Section 3). Then, the current status of the literature is synthesised (Section 4). Future directions for advancing brand advocacy research are presented in the subsequent section (Section 5).

Brand advocacy is defined as the active promotion and support of a brand by consumers, driven by their strong connection and satisfaction with the brand, often expressed through various forms of consumer communication such as WOM, recommendations and online interactions (Jillapalli and Wilcox, 2010; Wilk et al., 2019). Scholars regard brand advocacy as the outcome of customer loyalty (Wilk et al., 2019; Quaye et al., 2022), commitment (Badrinarayanan and Laverie, 2013) and attachment (Shimul and Phau, 2018, 2022; Potdar et al., 2018) to the brands. Customers defending a brand also advocate for the brand (Parrott et al., 2015). Customer satisfaction and positive experiences with the brand often initiate other attributes that satisfy the criteria of brand advocacy (Jillapalli and Wilcox, 2010; Shukla et al., 2016). Customers achieving the desired value often instil a sense of satisfaction and catalyse their involvement in brand advocacy (Albert et al., 2013).

Conceptual differences exist between brand advocacy and related constructs such as brand promotion, endorsement, evangelism, support and loyalty. Brand loyalty, while manifesting in various forms, does not necessarily encompass the fundamental characteristics of brand advocacy. The mere act of repurchasing does not guarantee customers’ willingness to advocate for the brand. As Moliner-Tena et al. (2019, p. 734) emphasise, “advocacy is a much more powerful indicator of real consumer loyalty than repeat purchase behaviour because consumers only endorse products, services, brands or firms if they feel strongly about them”. Brand support and evangelism may lack focus without customers’ self-identification or relationship-building with the brand (Wilk et al., 2021). The proliferation of social networking sites has led to extensive analysis of online and offline customer involvement, examining both positive and negative WOM’s impact on brand advocacy (Keller, 2007; Wallace et al., 2012, 2014). For instance, monetised online brand promotion through social media influencers differs fundamentally from genuine brand advocacy, as it lacks the “strong, passionate, explicit and ongoing” commitment to brand promotion. Similarly, celebrity brand endorsement as a promotional strategy diverges from authentic customer advocacy, which is characterised by voluntary, proactive support and defence of brands across platforms. This complex and evolving nature of brand advocacy, coupled with fragmented literature, necessitates a systematic review to consolidate existing knowledge and identify future research directions.

To better understand the current state of the brand advocacy literature, a scoping review was conducted following established protocols (Arksey and O'Malley, 2005; Tricco et al., 2016). A scoping review is a systematic approach to outlining key concepts, types of evidence and research gaps in a defined field by comprehensively examining existing literature (see Munn et al., 2018 for a review). This methodology is appropriate for brand advocacy research given its emerging nature and diverse conceptualisations across marketing domains, similar to recent scoping reviews in marketing (Hao et al., 2024; Veloutsou and Liao, 2023; Chen et al., 2024). This review followed five systematic steps:

1. setting research questions;

2. identifying relevant studies;

3. selecting studies based on inclusion/exclusion criteria;

4. extracting and organising data; and

5. collating, summarising and reporting results.

This structured approach ensures comprehensive coverage while maintaining methodological rigour in synthesising the brand advocacy literature.

This scoping review intends to reveal the current state of brand advocacy research and provide future research directions. Prior research disparately examines brand advocacy in terms of its antecedents, outcomes and contexts. It is necessary to comprehend the distinctiveness of research on each of the components and their interrelationships. This review aims to answer the following four research questions: What are the key theoretical foundations and definitional boundaries of brand advocacy in current literature? What methodological approaches and measurement scales have been used in brand advocacy research? What are the primary antecedents, outcomes, mediators and moderators of brand advocacy across different contexts? How can future research advance theoretical understanding and practical applications of brand advocacy?

We searched for relevant research articles in prominent databases, namely, Scopus, Web of Science and ProQuest. The search was conducted across titles, abstracts and keywords of the peer-reviewed journal articles published only in the English language. To identify appropriate search terms for brand advocacy literature, this review used the “backward and forward approaches” (Levy and Ellis, 2006; Veloutsou and Liao, 2023). Several variations in the search strings were deployed, namely, “brand advocacy” OR “consumer advocacy” OR “customer advocacy” OR “brand advocate” OR “advocacy intention” OR “willingness to advocate”. The literature search was finalised in June 2025, during the second round of revision of this review. A total of 704 papers were retrieved through searches in the aforementioned databases, from which 166 duplicate records were removed. This resulted in 538 unique records following the initial search.

A set of parameters for including and excluding journal articles, as suggested by the established guidelines, was used in the article selection process (Munn et al., 2018). In line with prior reviews (Spasojevic et al., 2018), only papers published in the Australian Business Dean Council (ABDC) list were included. Accordingly, 155 papers not listed in the ABDC ranking were removed, resulting in 383 records retained. A systematic screening process was then conducted to assess each paper’s relevance and appropriateness for this scoping review. All papers were independently reviewed to minimise subjective bias, with clear inclusion criteria requiring that papers must substantively address brand advocacy as a core construct rather than merely mentioning it peripherally. Both theoretical relevance assessment and methodological appropriateness were assessed. Through this rigorous evaluation process, 211 papers that met the search criteria regarding keywords but did not address the fundamental aspects of brand advocacy were excluded. For example, some papers had the words “brand” and “advocacy” in the abstract, but they did not examine brand advocacy as a construct. A total of 172 journal articles were included for synthesis and analysis in this review after a full-text reading. The article selection process is summarised in Figure 1.

Data extraction was conducted using a structured protocol, with all articles being independently coded by three authors. Data on theory, context, respondents’ country analytical method, measurement scale, antecedents, outcomes, mediator and moderator were extracted. The extracted data were organised in Microsoft Excel, where thematic analysis was performed to identify patterns and research gaps in the brand advocacy literature. Regular team meetings were held to discuss and resolve coding discrepancies and ensure consistency in the data extraction process.

Publication trends show that there has been a growing interest in research on brand advocacy since 2018 (Supplementary Table 1). Of the research articles reviewed in this paper, the Journal of Product & Brand Management (19 papers), the Journal of Business Research (11 papers) and Marketing Intelligence & Planning (8 papers) were the most prominent outlets. Regarding geographic contexts, while not all studies reported their study locations, research was primarily conducted in the USA and India, with Australia also featuring notably. Supplementary Table 2 provides a detailed breakdown of these studies by country, illustrating the global reach and varied settings of brand advocacy research.

Brand advocacy research has broadly explored the concept’s applicability in various contexts. Among the studies that reported the context of their research, social media marketing emerges as an influential context, where brand advocacy behaviours are transformed by digital affordances that amplify consumer voices and create new brand advocacy channels beyond traditional WOM (Choi et al., 2021; Wallace et al., 2014). This digital transformation has reshaped brand advocacy from primarily private recommendations to public endorsements with broader reach and visibility.

Corporate social responsibility (CSR) represents another significant domain, with studies revealing how ethical brand actions create deeper emotional connections that drive brand advocacy behaviours. Notably, research shows that CSR-driven brand advocacy tends to be more resilient and values-based than brand advocacy motivated solely by functional benefits (Du et al., 2007). The luxury sector demonstrates distinctive brand advocacy patterns, where exclusivity and self-expression motivate consumers to become brand ambassadors (Shimul and Phau, 2022). In contrast, utilitarian values often play a larger role in non-luxury contexts.

Destination branding research has documented how emotional attachments to places generate particularly passionate advocacy driven by personal identity connections (Aksoy and Yazici, 2025; Rather et al., 2022). Meanwhile, service contexts such as banking and higher education reveal how interpersonal relationships influence brand advocacy intentions (Moliner et al., 2018; Bakirtas and Gulpinar Demirci, 2022). Likewise, cross-contextual analysis shows that brand advocacy mechanisms vary by industry, such as emotional drivers predominating in experiential categories (tourism and luxury), while trust and functional satisfaction play larger roles in utilitarian contexts. Table 1 summarises the key contexts and their distinctive brand advocacy characteristics.

Social identity theory (SIT): According to SIT, individuals enhance their self-esteem and define their social identity by affiliating with groups that reflect their values and characteristics (Tajfel, 1978). This affiliation leads them to internalise the successes and failures of these groups as their own (Ashforth and Mael, 1989). In the context of brand advocacy, this identification process occurs when the brand becomes a key element of their self-concept and fulfils the needs such as self-categorisation, self-distinctiveness and self-enhancement (Becerra and Badrinarayanan, 2013). For example, Balaji et al. (2016) find that strong identification with a university significantly enhances students’ self-concept, commitment and brand advocacy intention. Similarly, frontline employees who align with a brand’s values are more likely to engage in brand advocacy, whereby they express their identities through support for the brand (Schepers and Nijssen, 2018).

Social exchange theory (SET): The SET is based on the principle that social interactions involve exchanges of valuable resources between parties (Emerson, 1976). Drawing on SET, studies found that consumers engage in brand advocacy as a form of reciprocity for positive interactions with a brand (Choi et al., 2021). When brands take proactive actions that provide value, consumers will likely respond by advocating for the brand on social media, thereby increasing their emotional connection to it. This behaviour is not just about sharing information; it involves the exchange of brand-related emotions and the generation of engagement, both of which are essential elements of online brand advocacy (Wilk et al., 2021; Potdar et al., 2018). The concept of social currency, where valuable resources and information are exchanged in digital interactions, explains how online exchanges can build and sustain new advocacy relationships (Trudeau and Shobeiri, 2016).

Self-congruity theory: The self-congruity theory examines how customers mentally compare and choose brands that align with their personality attributes and values (Elbedweihy et al., 2016). This alignment influences purchasing decisions and WOM through various self-concept dimensions like actual, ideal and social self (Sirgy et al., 2008). Research demonstrates that self-brand identification drives positive brand attitudes, as it reinforces consumers’ desired self-image (Shimul and Phau, 2022; Moliner et al., 2018). Customers are more inclined to advocate for brands that match their self-perceptions (Liu et al., 2012) when they perceive strong value alignment (Rather et al., 2020). That is, once consumers integrate a brand into their self-concept, this connection motivates brand advocacy as part of their identity expression (Moliner et al., 2018). For instance, strong congruity between game content and brand identity increases positive brand thoughts and brand advocacy behaviour (Vashisht et al., 2021).

Attachment theory: The attachment theory explains individuals’ personal and emotional connections to objects or materials they perceive as valuable and desirable (Bowlby, 1977). Studies have explored the impact of customers’ emotional attachments to brands that fulfil their requirements for desirability and security (Shimul and Phau, 2022). Research has shown that the intensity of this emotional bond often impacts how much customers are willing to maintain their relationship with the brand and advocate for it (VanMeter et al., 2015; Sanz-Blas et al., 2019). The emotional bond between customers and brands strengthens over time as customers gain brand experience, cultivate a sense of connectedness and, subsequently, engage in brand advocacy (Ahmadi and Ataei, 2022). For instance, in destination marketing, the attachment theory explains how travellers’ identification with a destination brand leads to brand advocacy, fulfilling social identity objectives (Kumar and Kaushik, 2017). As customers’ experiences with a brand deepen over time, their attachment grows, leading to increased brand advocacy as they integrate the brand into their self-concept.

Beyond the aforementioned four primary theories, brand advocacy research has used several other theoretical lenses (Table 2). Self-determination theory has been applied to examine how autonomy and competence influence brand advocacy (Bilro and Loureiro, 2023; Jillapalli and Wilcox, 2010), while social influence theory explores how interpersonal connections shape brand advocacy decisions (Confetto et al., 2023; Jayasimha et al., 2017; Wilk et al., 2024). Attribution theory has also been used to understand how consumers interpret brand behaviours and motives (Ahmad et al., 2023; Kim, 2024). More recent research has used specialised frameworks such as the triangular theory of love (Kang, 2018) and the stimulus-organism-response model (Aljarah et al., 2024; Atsiz et al., 2024) to examine the emotional and cognitive dimensions of brand advocacy.

Studies measuring brand advocacy often lack consistency in their measurement sources, with researchers drawing from diverse scales that are often used in unintended ways. For instance, multiple papers (Srinaruewan et al., 2015; Du et al., 2007; Xie et al., 2019; Pai et al., 2015; Bilro et al., 2018) adapted scale items from Bhattacharya and Sen (2003) to measure brand advocacy. However, a closer look at the referenced source reveals that Bhattacharya and Sen (2003) did not intend these items to measure brand advocacy. Rather, they proposed a set of “potential measures” to assess the constructs entitled “consumer-company identification”, of which following are frequently used to measure brand advocacy:

• intention to try new products of the brand;

• favourable WOM; and

• resilience to negative information.

Other brand advocacy measurement scales have evolved through various adaptations in academic research. Several studies (Sharma et al., 2022; Kim et al., 2023; Ahmadi and Ataei, 2022) have used Kim et al.’s (2001)WOM measures, which were originally adapted from File et al. (1994). Another prominent measure is Melancon et al.’s (2011) four-item advocacy scale, which has been widely used in recent brand advocacy research (Badenes-Rocha et al., 2022; Choi et al., 2021). Some researchers have combined items from Brown et al.’s (2005)WOM measures with Ahearne et al.’s (2005) customer extra-role behaviour scales (Kumar and Kaushik, 2017, 2020). Fullerton’s (2005) adaptation of Zeithaml et al.’s (1996) items has been influential in measuring advocacy intention (Mathur, 2019). In retail contexts, researchers have adapted scales from Badrinarayanan and Laverie (2011) to assess salesperson brand advocacy (Gammoh et al., 2021). Further, conceptual similarities have resulted in researchers using scales meant to measure brand love (Carroll and Ahuvia, 2006), brand acceptance (Du et al., 2007) and self-identification measures (Melancon et al., 2011; Stokburger-Sauer et al., 2012) for the assessment of brand advocacy (Wallace et al., 2012, 2014; Samala and Singh, 2019). Supplementary Table 3 outlines five widely used scales and their adapted versions in brand advocacy research.

The existing literature has examined a set of drivers of brand advocacy (Supplementary Table 4). As delineated above (Section 4.2.1), consumers’ identities, specifically their belongingness to groups and communities, play a key role in driving brand advocacy. Studies show that individuals view themselves as part of social groups, with this sense of belonging influencing their behaviour towards the group, including brands (Mandl and Hogreve, 2020). Such identification with a brand leads consumers to engage in collective behaviours (i.e. brand advocacy) to commend the brand’s virtues and assist other brand members, driven by the desire for self-enhancement and perceived self-congruence (Shimul and Phau, 2022; Rather et al., 2022). Individuals who psychologically connect with a brand and see its successes and failures as their own are more likely to demonstrate favouritism and engage in behaviours that benefit the brand, such as advocating for the brand to others (Becerra and Badrinarayanan, 2013; Kumar and Kaushik, 2017). Taken together, consumer brand identification results in a reciprocal relationship when consumers feel affiliated with the brand community, they support the brand and serve as brand advocates (Wilk et al., 2021; Coelho et al., 2019).

Such reciprocal relationships also make consumers more engaged with the brand, resulting in brand advocacy. Harrigan et al. (2021) argued that engaged consumers are likely to be brand advocates, as higher levels of consumer interactions with the brand lead to increased motivation, favourable attitudes, loyalty and recommendations, making brand advocacy a consequence of engagement. For instance, consumers’ engagement in services comes from interactive and shared experiences, which motivates them to advocate for a particular service provider to others (Moliner et al., 2018). This finding has been empirically supported across research on brand advocacy in social media (Ballester et al., 2023; Mathur, 2019), fashion branding (Samala and Singh, 2019), destination branding (Kumar and Kaushik, 2020) and virtual reality marketing (de Regt et al., 2021). Studies reveal multiple interconnected antecedents, with self-congruity emerging as significant through social media (Wallace et al., 2012, 2014) and sports brand contexts (Wong and Hung, 2023). Consumers’ self-brand identification and engagement augment emotional connections (Bagozzi et al., 2021), whilst emotional attachments, including brand love and intimacy, drive brand advocacy (Roy et al., 2023). When emotionally invested, consumers view brands as self-extensions, actively promoting and defending them (Ahmadi and Ataei, 2022). Furthermore, trust, commitment and satisfaction significantly influence brand advocacy, with brand trust and perceived integrity proving essential for endorsement (Becerra and Badrinarayanan, 2013). CSR initiatives enhance brand advocacy when driven by public-serving motivations (Aljarah et al., 2022).

The outcomes of brand advocacy encompass a range of impacts on consumers and brands that unearth the multifaceted effects of consumer-driven promotions in the marketplace (Supplementary Table 5). The connection between consumer and brand cultivates brand trust and loyalty (Wilk et al., 2019, 2021; Roy et al., 2023; Quaye et al., 2022), both of which often stimulate brand advocacy behaviour. Consumers’ intention to support brands nurtures their behaviour towards the brands, (re)purchase intentions (Wilk et al., 2019, 2021; Choi et al., 2021; Dutta et al., 2021; Keller, 2007; Mandl and Hogreve, 2020) and recommendation decisions (Keller, 2007). Alongside these connections, brand advocacy manifests through various customer behaviours, from social media promotions and favourable WOM (Potdar et al., 2018) to information sharing (Badenes-Rocha et al., 2022). Such behaviours generate social currency as consumers benefit from brand-related information exchange (Trudeau and Shobeiri, 2016). Understanding brands’ intrinsic and extrinsic motives enhances customer engagement and brand equity (Pai et al., 2015). Conversely, brand avoidance may occur when negative experiences intersect with community engagement (Jayasimha et al., 2017). Studies also document that brand representation across platforms influences customer attitudes and brand reviews (Ghosh, 2018) while affecting social and perceived brand value (Campbell et al., 2024; France et al., 2018). Nevertheless, employee advocacy also plays an important role, with research emphasising the impact of staff emotions and brand identification on customer interactions (Aksoy et al., 2023; Gammoh et al., 2021).

Research reveals various mediating mechanisms in brand advocacy’s antecedents and outcomes (Supplementary Table 6), which shows the complex interplay between consumers, brands and brand advocacy. Emotional connections emerge as significant mediators, with emotional attachment mediating the relationship between brand reputation and brand advocacy (Ahmadi and Ataei, 2022), while brand love mediates the relationship between brand community and brand advocacy (Coelho et al., 2019). Brand relationship quality and trust serve as mediators in the brand advocacy–loyalty relationship (Quaye et al., 2022).

In service marketing contexts, service quality mediates the relationship between affective commitment and brand advocacy, with committed customers exhibiting brand advocacy when perceiving high service quality (van Tonder and Petzer, 2021). CSR initiatives influence brand advocacy through brand trust and customer–brand identification as mediating factors (Limbu et al., 2020). Kim et al. (2023) found that perceived value-driven motivation mediates the relationship between institutional CSR and brand advocacy intentions. Additional mediating relationships include thought favourability in game–product fit contexts (Vashisht et al., 2021), customer-based brand equity in counterfeit awareness scenarios (Baghi et al., 2016) and brand engagement with self-concept in Millennial fashion brands (Samala and Singh, 2019). Brand loyalty also serves as a mediator between brand passion and brand advocacy (Pourazad et al., 2020), demonstrating the multifaceted nature of brand advocacy relationships.

Several studies have investigated moderating variables, yielding intriguing findings that enhance understanding of the underpinnings of brand advocacy and its associations with pertinent constructs (Supplementary Table 7). Research examining moderating factors to brand advocacy effects reveals several significant relationship dynamics. Brand relationship quality constructs demonstrate important interactive effects, with emotional brand attachment moderating consumer-based brand equity’s impact on brand advocacy (Baghi et al., 2016). Brand loyalty strengthens the attachment–advocacy relationship in luxury contexts (Shimul and Phau, 2018), while brand engagement amplifies the connection between brand identification and brand advocacy (Rather et al., 2022).

CSR activities show notable moderating effects, with CSR-emphasising brands generating stronger consumer identification and brand advocacy (Srinaruewan et al., 2015). The impact varies across contexts, such as private versus public hospitals (Limbu et al., 2020), while in B2B settings, intrinsic CSR motives strengthen the relationship between CSR perceptions and brand advocacy (Pai et al., 2015). Social media engagement presents distinct moderating patterns, with content creators showing stronger relationships between affective commitment and brand advocacy compared to content consumers (Turri et al., 2013). Service contexts reveal that inadequate provider responses and service issue severity moderate the brand advocacy–brand avoidance relationship (Jayasimha et al., 2017). Organisational identification also strengthens the relationship between trust and employee online brand advocacy (Aksoy et al., 2023).

This scoping review of brand advocacy research reveals a strong preference for quantitative approaches (96%), with structural equation modelling (SEM) emerging as the overwhelmingly dominant analytical technique. Specifically, 98 studies applied SEM in AMOS (Aksoy et al., 2023; Wilk et al., 2021; Choi et al., 2021; Coelho et al., 2019; Shimul and Phau, 2018; Kang, 2018) and PLS-SEM (Bilro and Loureiro, 2023; Quaye et al., 2022; Harrigan et al., 2021), PLS (Hsiao et al., 2015) and SmartPLS (Gammoh et al., 2021; Hao et al., 2024). Other common techniques included regression analysis (13 studies) (Limbu et al., 2020; Fullerton, 2005) and experimental design (12 studies) (Badenes-Rocha et al., 2022; Liao et al., 2025). Beyond these mainstream approaches, a limited number of studies used specialised techniques, including qualitative analysis (Wilk et al., 2021), path analysis (Thomas and Jain, 2022), factor analysis (Dutta et al., 2021), meta-analysis (Bhati and Verma, 2020), SPSS macro syntax PROCESS (Mandl and Hogreve, 2020) and netnography with content analysis (Potdar et al., 2018; Parrott et al., 2015). This methodological trajectory reflects the domain’s development towards increasingly sophisticated modelling capabilities while maintaining predominantly positivist paradigms. Nevertheless, the limited presence of qualitative (eight studies) and mixed-method approaches (four studies) suggests opportunities for methodological diversification in future research.

Current research on brand advocacy predominantly uses customer–brand relationship theories. Theoretical diversification could significantly enhance conceptual understanding. For instance, social adaptation theory (Kahle and Homer, 1985) can be used to examine how consumers adjust advocacy behaviours during brand transformations like rebranding. Social cognition theory (Swann, 1984) could illuminate information processing in advocacy decisions and recommend effective positioning strategies. Self-presentation theory (Baumeister and Hutton, 1987) provides insights into how consumers strategically manage public image through brand behaviours. Stakeholder theory (Friedman and Miles, 2002) presents a comprehensive perspective for examining how interactions between brands and key stakeholders, including employees, customers and partners, influence brand advocacy. This theoretical framework could enhance understanding of how integrated stakeholder engagement strategies contribute to sustained brand advocacy. These complementary theoretical approaches collectively offer the potential for developing a more nuanced understanding of the cognitive, social and organisational dynamics that shape brand advocacy behaviours.

Future research could extend findings reported here by meticulously analysing unexplored and novel avenues that incorporate new dimensions into brand advocacy research. For instance, Weiger et al. (2025) found that customers who advocate for a brand on social media may reduce their own purchase frequency, which challenges the assumption that advocacy always translates into greater loyalty. Within luxury branding, strategic comparison across brand life cycle stages can provide insights into how advocacy varies between established versus emerging brands (Shukla et al., 2016). While formal educational institutions have been extensively studied (Balaji et al., 2016; Jillapalli and Wilcox, 2010), examining online-based private educational platforms’ (e.g. Khan Academy) branding strategies and communication tactics can introduce novel constructs. AI integration may impact brand advocacy by generating deeper emotional connections through personalised interactions (Huang and Rust, 2021) that warrant investigation of psychological effects across cultural contexts. While CSR’s influence is well-documented (Du et al., 2007; Limbu et al., 2020), scholars advocate granular analysis alongside emerging influencer marketing opportunities (VanMeter et al., 2015). Future trajectories span rapidly transforming industries, whilst tourism studies could expand beyond international visitors (Malik, 2021) to domestic perspectives. Nation branding research warrants investigating stakeholder coordination’s impact, with cross-cultural variables offering opportunities to enrich theoretical frameworks.

While extant brand advocacy research has identified numerous contributory variables, brand advocacy research requires investigation of novel antecedents, particularly temporal relationship dynamics, with brand promotions shaping credibility through social networks (Wallace et al., 2012) and personalised content impacting behaviour (Choi et al., 2021). Brand influencers, employee–customer interactions (Badrinarayanan and Sierra, 2018) and brand communities’ resource-sharing mechanisms (Mandl and Hogreve, 2020; Jayasimha et al., 2017) warrant examination. Future research should investigate how prior knowledge and brand experience create customer resilience to negative information, as current literature shows inconsistent findings regarding whether prior experience positively moderates advocacy behaviours or creates diminishing returns, which warrants an examination of boundary conditions that explain these contradictory results. Regarding CSR initiatives, disagreement exists in the literature about which dimensions (social, economic and environmental) most effectively drive advocacy. Research provides conflicting evidence about whether consumers’ moral versus self-serving motives create stronger responses. Therefore, this review calls for novel theoretical frameworks to examine interactive effects between CSR dimensions and motivational orientations, including potential curvilinear relationships explaining mixed results. Brand bravery represents an understudied antecedent lacking theoretical consensus. Brands addressing and mitigating critical misconduct of internal or external factors bravely can also influence and generate customer support or manipulate undesired customer reactions (e.g. brand boycotting).

Brand advocacy can have a positive impact on brand growth by leveraging satisfied customers’ influence, trust and positive WOM, leading to increased visibility, credibility, loyalty and revenue. Thus, additional research is necessary to analyse whether companies can ensure brand growth and expansion through brand advocacy. Future research could also analyse the marketing and corporate strategies of brands to ascertain desirable outcomes through brand advocacy. Brand advocacy may influence companies to maintain authenticity and quality while prioritising customer satisfaction, motivating consistent promise delivery and nurturing positive experiences that contribute to sustained growth, with customer citizenship behaviour requiring investigation as a potential advocacy outcome. While brand advocacy results in positive consumer–brand relationships, it may introduce unintended challenges requiring study. Despite enhanced engagement potential, positive advocacy can transform into anti-brand communication. Brand advocates’ dissonance from unmet expectations warrants research to examine how ineffective strategies precipitate retaliation and negative WOM dissemination. The dissonance experienced by brand advocates when expectations are unmet calls for research into how ineffective strategies may precipitate consumer retaliation and the spread of negative WOM. Future research should also explore the dark side of brand advocacy, including cases where unmet expectations lead to brand hate or anti-brand behaviour (e.g. public criticism or boycotts), highlighting the fragile nature of advocate–brand relationships.

Future research in brand advocacy warrants the examination of multiple mediating variables, as current literature shows limited consensus on which mechanisms best explain advocacy relationships. While perceived brand value has been suggested as a mediator between brand advocacy and customer loyalty, empirical validation remains insufficient about its relative importance compared to other mediators, like emotional attachment, which merits investigation. Self-brand identification could explain how brand preference connects to advocacy through customer–brand alignment. Brand distinctiveness, warmth and positioning warrant examination as mediators between brand perception and brand advocacy. Memorable brand experiences present promising mediating opportunities, particularly for outcomes like commitment and attachment. The impact of brand personality on advocacy–trust relationships and community attitudes should also be investigated. Customer motivations, whether social, brand-centric or personal, may mediate between citizenship behaviours and firm initiatives like CSR and brand activism through value alignment, offering strategic implications for brand management.

Research indicates positive correlations between self-expressive brands and favourable WOM, with Carroll and Ahuvia (2006) highlighting brand love’s role in strengthening this relationship. Current brand advocacy research often examines moderators in isolation, which creates an incomplete understanding of advocacy dynamics. The multifaceted nature of consumer–brand relationships suggests multiple moderators may interact simultaneously; as such, brand authenticity may only influence advocacy when combined with specific motivations or attachment levels. This complexity demands examining multiple moderating variables concurrently, including interactive effects between brand authenticity and success/failure conditions, brand uniqueness and attachment influences and how intrinsic versus extrinsic motivations amplify other moderating effects. Likewise, consumer ethnocentrism and cosmopolitanism warrant investigation regarding their moderating effects on the relationship between brand commitment and brand advocacy. In the context of internal branding, employee-related variables, including emotional intelligence and incentive structures, merit examination as potential moderators of customer engagement and brand advocacy. Social media research could explore how visual attention to brand content and cause-related movements influences brand-related behaviours. Demographic factors (e.g. education and age) present promising avenues for investigation, especially concerning their impact on CSR-driven brand advocacy intentions, given observations that younger, educated customers demonstrate a heightened awareness of brands’ CSR activities.

The review of measurement scales (Section 4.4.1) reveals that most studies have adapted WOM-related scales to measure brand advocacy. However, the critical question remains whether these scales truly capture the construct of brand advocacy as defined in the literature. Moreover, despite the widespread use of these adapted measures, there is limited research explicitly validating these scales as reliable and valid indicators of brand advocacy. This lack of empirical support suggests a potential gap in the literature. Therefore, this review calls for future research to develop and validate a dedicated brand advocacy scale.

Advancing methodological rigour in brand advocacy research needs diverse analytical approaches. Longitudinal studies offer valuable insights into evolving customer–brand relationships and brand advocacy dynamics, whilst experimental designs can establish causality across varying contexts, particularly in comparing luxury versus regular brands. Neuromarketing methods, including brain imaging and biometric analysis, present opportunities for understanding brand advocacy’s subconscious drivers, complementing traditional research approaches. Secondary data analysis enables trend identification and benchmarking, while case studies provide context-rich insights for theoretical framework development. The integration of qualitative methods, particularly in-depth interviews, alongside neural techniques for examining emotional responses, could enhance understanding of both positive and negative brand advocacy outcomes, including brand defence and brand hatred. The use of a multiplex of methods to explore brand advocacy promises to significantly advance understanding of the construct, both theoretically and practically.

This scoping review makes significant theoretical contributions to the brand advocacy research. While Bhati and Verma’s (2020) meta-analysis focused solely on antecedents, this comprehensive examination provides the first systematic mapping of the entire brand advocacy nomological network, including theoretical foundations, mediators, moderators and outcomes across diverse contexts. The identification of four primary theoretical foundations (SIT, SET, self-congruity theory and attachment theory) provides the systematic theoretical framework for the construct, which extends the atheoretical approaches that have dominated prior research. The review also reveals significant measurement inconsistencies, with most studies inappropriately adapting WOM scales rather than developing dedicated brand advocacy measures, which is a fundamental issue overlooked in previous reviews. To advance research on brand advocacy further, this review provides a set of research questions (Table 3) and a framework (Figure 2) that outline areas to explore the drivers, outcomes and contexts of brand advocacy, including the impact of AI, CSR initiatives and industry and cultural dynamics.

For practitioners, this review provides guidance in developing effective brand advocacy strategies. Brand managers can leverage the framework (Figure 2) to identify the most impactful drivers of advocacy, such as recognising the role of emotional connections and brand identification in generating brand advocacy. For example, premium brands (e.g. Apple) often leverage self-congruity by aligning products with customers’ identity aspirations (Liao et al., 2021), whilst Patagonia’s environmental activism exemplifies how genuine CSR commitment generates values-based advocacy (Bulmer et al., 2024). The analysis of contextual factors shows how service brands (e.g. Southwest Airlines) should invest in employee empowerment programs to deliver exceptional customer experiences that drive brand advocacy behaviours (Convery-Pelletier, 2024). As emerging technologies like AI continue transforming customer–brand relationships, this review will equip marketers with the knowledge to develop differentiated brand advocacy strategies that align with evolving consumer expectations. This review emphasises the importance of developing proprietary advocacy metrics rather than relying on adapted WOM scales, enabling more precise tracking of advocacy effectiveness across brand touchpoints.

Limitations: While this scoping review used rigorous search protocols, several methodological constraints warrant acknowledgment. The reliance on three primary databases (Web of Science, Scopus and ProQuest) potentially excluded valuable contributions indexed elsewhere. Also, the stringent focus on ABDC-ranked publications may have overlooked important insights from unpublished works (e.g. dissertations), practitioner-oriented journals, conference proceedings and emerging open-access platforms. Finally, incorporating international publications beyond English-language sources would enhance the global applicability of future frameworks.

The authors extend their sincere gratitude to the Editors, Associate Editor and anonymous peer reviewers for their valuable constructive feedback and developmental suggestions, which contributed to enhancing the quality and rigour of this manuscript.

The author contributions are as follows: Anwar Sadat Shimul: Writing – review and editing, Writing – original draft, Project administration, Methodology, Investigation, Formal analysis and Conceptualisation; Anisur R. Faroque: Writing – review and editing, Writing – original draft, Project administration, Methodology and Conceptualisation; and Esnaina Quader: Writing – original draft, Project administration, Methodology, Investigation, Data curation and Formal analysis.

The supplementary material for this article can be found online.