Pooshing the Boundaries of Instagram Influencers: How Mainstream vs. Micro-celebrity Influencers Impact Source Credibility, Parasocial Interaction, and Intent to Follow

Individuals are increasingly turning to health influencers on social media for advice about nutrition, exercise, wellness, and more. This study addressed the impacts of two mechanisms of social influence—source credibility and parasocial interaction—on intent to follow health influencers. An online experiment of 202 participants was conducted to compare a celebrity health influencer and a micro-celebrity health influencer on Instagram. Results showed the micro-influencer had higher source credibility and parasocial interaction. A mediation model detected an indirect relationship between influencer and intent to follow, with parasocial interaction as the mediator. This implies that health communicators who want to increase their social media followers feature down-to-earth influencers who inspire familiarity and desire to learn more about the influencer.