Table 1. Literature review on source and... | Emerald Publishing

Table 1.

Literature review on source and message characteristics affecting consumer responses to influencer marketing

Paper	Method/social platform	Source and message characteristics	Key findings
Jin and Phua, 2014	Experiments/Twitter	Number of followers Source credibility	Higher number of followers increases source credibility and intention to build an online friendship. The joint impact of high number of followers and positive valence increases buying intention and product involvement
Uribe et al., 2016	Experiment/online blog	Communicator expertise Message sidedness Advertising intent	The relevance of using two-sided messages, expert sources and unbiased (nonsponsored) messages in terms of increase blog credibility and behavioral intention toward the reviewed product
De Veirman et al., 2017	Online experiment/Instagram	Number of followers Divergent products	Influencers with a higher number of followers is perceived as more popular and is ascribed more opinion leadership, and therefore, people have more positive attitudes toward this influencer. If influencers with high numbers of followers promote divergent products, this decreases the brand’s perceived uniqueness and, consequently, brand attitudes
Xiao et al., 2018	Online survey/YouTube	Source trustworthiness Argument quality	Trustworthiness, social influence, argument quality and information involvement are influential factors affecting consumer perceived information credibility on YouTube
Balabanis and Chatzopoulou, 2019	Online survey/online blog	Blogger credibility Blogger authority and homophily Message usefulness	Information seekers’ objectives and issue involvements are important drivers of blog selection and determinants of the blog’s influence
Lou and Yuan, 2019	Online survey/social platforms	Influencers credibility Informative and entertainment value of message content	The informative value of influencer-generated content, influencer’s trustworthiness, attractiveness and similarity to the followers positively affect followers’ trust in influencers’ branded posts, which subsequently influence brand awareness and purchase intentions
De Vries, 2019	Online experiment/Instagram	Likes-to-followers ratio Number of hashtags Perceived account credibility	High as well as low likes-to-followers ratios negatively influence the perceived credibility of the account. The addition of hashtags is identified as a way to guard against the negative impact of high likes-to-followers ratios
Boerman, 2020	Online experiment/Instagram	Number of followers Instagram disclosure	Disclosure positively affects brand recall and intentions to engage with the post via ad recognition Influencer type does not moderate the effect of the disclosure and does not affect people's responses
De Veirman and Hudders, 2020	Online experiment/Instagram	Influencer credibility Instagram disclosure Message sidedness	Including a sponsorship disclosure negatively affects brand attitude through enhanced ad recognition, which activates ad skepticism, which, in turn, negatively affects the influencer’s credibility. The effect is present when the influencer used a one-sided message and not when the message was two-sided
Kay et al., 2020	Online experiment/Instagram	Number of likes Instagram disclosure	Consumers exposed to the micro-influencer condition report higher levels of product knowledge and consumers exposed to the disclosure condition reported the products endorsed by SMIs to be more attractive
Schouten et al., 2020	Online experiment/online platform	Influencer vs celebrity Perceived credibility	Users identify more with influencers than celebrities, feel more similar to influencers than celebrities and trust influencers more than celebrities. Similarity, wishful identification and trust mediate the relationship between type of endorser and advertising effectiveness
Balaji et al., 2021	Online experiment/Instagram	Message construal Message valence Credibility	Low-construal messages posted by the nanoinfluencer are viewed as more credible than high-construal messages. Positively framed low-construal messages are perceived as more credible than negatively framed low-construal messages
Kim and Kim, 2021a	Online survey/Instagram	Sponsorship disclosure Influencer-product congruence	Influencer-product congruence enhances product attitude and reduces advertising recognition Sponsorship disclosure can also affect product attitude in a serial mediation of calculative motive inference and advertising recognition
Kim and Kim, 2021b	Online survey/Instagram	Influencer’s credibility and homophily Trust	Trust mediated the impacts of expertise, authenticity and homophily on loyalty and marketing outcomes. The moderating role of relationship strength was confirmed in authenticity-trust and trust-loyalty linkages
Lee and Theokary, 2021	Speech-to-text data, survey data, archival data/social platforms	Linguistic style Context expertise Production expertise Emotional contagion	Viewers of superstar SMIs identify the traditionally peripheral elements of linguistic style and emotional contagion as central to increasing the number of views and subscribers
Marques et al., 2021	Exploratory study/Instagram	Number of followers Clicks Likes Comments	Celebrity’s posts attracted more followers to the brand’s Instagram page when compared to the micro-influencer’s publications. However, the latter has garnered more clicks, comments and likes, thereby increasing the consumer-brand engagement through social media
The current study	Online experiment and lab (EEG) experiment/Instagram	Number of followers Source credibility Argument quality	Meso-influencers are perceived as a credible source of information only when their product-related post provides strong argument quality. Moreover, this process involves an increase in users’ cognitive work (measured with EEG)

Paper	Method/social platform	Source and message characteristics	Key findings
Jin and Phua, 2014	Experiments/Twitter	Number of followers Source credibility	Higher number of followers increases source credibility and intention to build an online friendship. The joint impact of high number of followers and positive valence increases buying intention and product involvement
Uribe et al., 2016	Experiment/online blog	Communicator expertise Message sidedness Advertising intent	The relevance of using two-sided messages, expert sources and unbiased (nonsponsored) messages in terms of increase blog credibility and behavioral intention toward the reviewed product
De Veirman et al., 2017	Online experiment/Instagram	Number of followers Divergent products	Influencers with a higher number of followers is perceived as more popular and is ascribed more opinion leadership, and therefore, people have more positive attitudes toward this influencer. If influencers with high numbers of followers promote divergent products, this decreases the brand’s perceived uniqueness and, consequently, brand attitudes
Xiao et al., 2018	Online survey/YouTube	Source trustworthiness Argument quality	Trustworthiness, social influence, argument quality and information involvement are influential factors affecting consumer perceived information credibility on YouTube
Balabanis and Chatzopoulou, 2019	Online survey/online blog	Blogger credibility Blogger authority and homophily Message usefulness	Information seekers’ objectives and issue involvements are important drivers of blog selection and determinants of the blog’s influence
Lou and Yuan, 2019	Online survey/social platforms	Influencers credibility Informative and entertainment value of message content	The informative value of influencer-generated content, influencer’s trustworthiness, attractiveness and similarity to the followers positively affect followers’ trust in influencers’ branded posts, which subsequently influence brand awareness and purchase intentions
De Vries, 2019	Online experiment/Instagram	Likes-to-followers ratio Number of hashtags Perceived account credibility	High as well as low likes-to-followers ratios negatively influence the perceived credibility of the account. The addition of hashtags is identified as a way to guard against the negative impact of high likes-to-followers ratios
Boerman, 2020	Online experiment/Instagram	Number of followers Instagram disclosure	Disclosure positively affects brand recall and intentions to engage with the post via ad recognition Influencer type does not moderate the effect of the disclosure and does not affect people's responses
De Veirman and Hudders, 2020	Online experiment/Instagram	Influencer credibility Instagram disclosure Message sidedness	Including a sponsorship disclosure negatively affects brand attitude through enhanced ad recognition, which activates ad skepticism, which, in turn, negatively affects the influencer’s credibility. The effect is present when the influencer used a one-sided message and not when the message was two-sided
Kay et al., 2020	Online experiment/Instagram	Number of likes Instagram disclosure	Consumers exposed to the micro-influencer condition report higher levels of product knowledge and consumers exposed to the disclosure condition reported the products endorsed by SMIs to be more attractive
Schouten et al., 2020	Online experiment/online platform	Influencer vs celebrity Perceived credibility	Users identify more with influencers than celebrities, feel more similar to influencers than celebrities and trust influencers more than celebrities. Similarity, wishful identification and trust mediate the relationship between type of endorser and advertising effectiveness
Balaji et al., 2021	Online experiment/Instagram	Message construal Message valence Credibility	Low-construal messages posted by the nanoinfluencer are viewed as more credible than high-construal messages. Positively framed low-construal messages are perceived as more credible than negatively framed low-construal messages
Kim and Kim, 2021a	Online survey/Instagram	Sponsorship disclosure Influencer-product congruence	Influencer-product congruence enhances product attitude and reduces advertising recognition Sponsorship disclosure can also affect product attitude in a serial mediation of calculative motive inference and advertising recognition
Kim and Kim, 2021b	Online survey/Instagram	Influencer’s credibility and homophily Trust	Trust mediated the impacts of expertise, authenticity and homophily on loyalty and marketing outcomes. The moderating role of relationship strength was confirmed in authenticity-trust and trust-loyalty linkages
Lee and Theokary, 2021	Speech-to-text data, survey data, archival data/social platforms	Linguistic style Context expertise Production expertise Emotional contagion	Viewers of superstar SMIs identify the traditionally peripheral elements of linguistic style and emotional contagion as central to increasing the number of views and subscribers
Marques et al., 2021	Exploratory study/Instagram	Number of followers Clicks Likes Comments	Celebrity’s posts attracted more followers to the brand’s Instagram page when compared to the micro-influencer’s publications. However, the latter has garnered more clicks, comments and likes, thereby increasing the consumer-brand engagement through social media
The current study	Online experiment and lab (EEG) experiment/Instagram	Number of followers Source credibility Argument quality	Meso-influencers are perceived as a credible source of information only when their product-related post provides strong argument quality. Moreover, this process involves an increase in users’ cognitive work (measured with EEG)