Meta‐analysis of social media influencer impact: Key antecedents and theoretical foundations

Abstract

This meta‐analytic review offers a comprehensive framework for studying social media influencers by integrating multiple theoretical perspectives and measures. It analyzes 250 effect sizes from 53 studies, highlighting the significance of credibility, trustworthiness, and perceived expertise of social media influencers in shaping attitudinal outcomes. Source Credibility Theory emerges as the most robust explanatory framework, while Parasocial Interaction Theory and Congruity Theory also play essential roles. For behavioral outcomes, Source Credibility Theory and Congruity Theory remain influential, with moderate effects observed for homophily and variables from the two‐step flow model. Methodological diversity, geographical context, platform context, product context, and influencer type contribute to variations in effect sizes. These findings provide insights into social media influencer influence dynamics and guide future research. Moreover, they contribute to theory development by shedding light on the mechanisms and conditions underlying social media influencer influence on consumer attitudes and behaviors.

Healthier but not happier? The lifestyle habits of health influencer followers

“…Instagram is one of the primary platforms for influencers, a term used to describe people who "shape audience attitudes through blogs, tweets and the use of other social media" (Freberg et al, 2011;pp. 90;Han & Balabanis, 2024). Influencers often embody a niche that they are experts in (Harrigan et al, 2021) and post content related to this niche.…”

“…Influencers often embody a niche that they are experts in (Harrigan et al, 2021) and post content related to this niche. Given that people tend to learn new patterns of behavior by observing others, particularly if they believe that person is an expert regarding the behavior (Bandura, 1971), influencers hold immense power to affect the thoughts and actions of those that follow them (Freberg et al, 2011;Han & Balabanis, 2024). Indeed, there is now substantial empirical evidence for the "influencer effect", or the myriad ways in which social media stars change the attitudes and behaviours of their followers (Han & Balabanis, 2024;Hudders et al, 2021).…”

“…Given that people tend to learn new patterns of behavior by observing others, particularly if they believe that person is an expert regarding the behavior (Bandura, 1971), influencers hold immense power to affect the thoughts and actions of those that follow them (Freberg et al, 2011;Han & Balabanis, 2024). Indeed, there is now substantial empirical evidence for the "influencer effect", or the myriad ways in which social media stars change the attitudes and behaviours of their followers (Han & Balabanis, 2024;Hudders et al, 2021). Although the effect of influencers is prominent in relation to marketing and consumer behaviour (Hudders et al, 2021), their influence extends to a much wider range of outcomes related to politics (Soares et al, 2018) and health (Engel et al, 2024;Powell & Pring, 2024).…”

“…Health influencer messaging may be even more influential in affecting health behavior engagement than traditional messaging channels because influencers are often perceived as more credible, trustworthy, knowledgeable, authentic and attractive than other message channels (reviewed in Han & Balabanis, 2024). Other mechanisms driving influencer effects include identification with and trust in influencers (compared to celebrities, Schouten et al, 2020), parasocial bonds (followers' identification and attachment with influencers), and homophily (followers' perception of similarity to influencers; Han & Balabanis, 2024).…”

The power of influence: How social media influencers are shaping consumer decision making in the digital age

“…It is marked by the emergence of social media influencers (SMI) as a game-changer in the field of marketing (Dwivedi et al, 2021;Hess et al, 2022;Hudders et al, 2021). Recent evidence indicates that the global social media user base exceeds 4.9 billion people (Forbes, 2023;Tuncer & Kartal, 2024), with 56% of consumers making decisions inspired by social media influencers (Han & Balabanis, 2024). As a result, businesses make effort to capture and maintain consumer attention.…”