The Effect of Influencer Image Types on Purchase Intention: The Mediating Role of Persuasion Knowledge and the Moderating Role of Parasocial Relationships.

Understanding how visual content shapes consumers' persuasion processes in social media environments has become an important research issue. Drawing primarily on the Persuasion Knowledge Model (PKM) and parasocial relationship (PSR) theory, while incorporating insights from self-reference theory and the Elaboration Likelihood Model (ELM), this study investigates how three Instagram image types-brand selfies, consumer selfies, and packshots-influence purchase intention through persuasion knowledge and examines the moderating role of PSR. A between-subjects experiment was conducted with 460 participants recruited through Amazon Mechanical Turk. The results revealed significant differences in persuasion knowledge and purchase intention across image types. Brand selfies were associated with lower levels of persuasion knowledge and higher purchase intention, whereas consumer selfies were associated with higher persuasion knowledge and lower purchase intention, with packshots showing intermediate effects. Persuasion knowledge mediated the relationship between image type and purchase intention, and PSR attenuated the negative effect of persuasion knowledge on purchase intention. These findings suggest that visual image composition itself can function as a persuasive cue and highlight the important role of relational context in shaping consumers' responses to persuasive intent in influencer marketing.