Big or Small? Impact of Influencer Characteristics on Influencer Success, with Special Focus on Micro- Versus Mega-Influencers

In influencer marketing, both mega-influencers (>1 million followers) and micro-influencers (10,000–100,000 followers) are successful. In this empirical study (n = 510), the underlying drivers of success based on key influencer characteristics were examined within the framework of a mediation model that analyzes trustworthiness, expertise, attractiveness, authenticity, and similarity as mediators of the relationship between influencer type and influencer success. All the variables proved to be significant mediators of attitudes toward influencers. Micro-influencers are superior in terms of trustworthiness, authenticity, and similarity, whereas mega-influencers outperform micro-influencers in terms of expertise and attractiveness. Mega-influencers are more successful than micro-influencers, based on key success variables (attitude toward and engagement with influencers). This study is the first to analyze the attractiveness and similarity of micro- and mega-influencers in a mediation model by contextualizing them based on previously investigated characteristics such as trustworthiness, expertise, and authenticity. This study contributes to the theoretical advancement of source credibility and source attractiveness models.