Authenticity, Trust, and AI Skepticism in Green Advertising: How AI and Human Endorsers Influence Purchase Intention in E-Commerce

Despite the growing use of artificial intelligence (AI) endorsers in advertising, evidence of their effectiveness remains mixed. This study examines how AI and human endorsers influence purchase intention in green e-commerce advertising through the parallel and sequential roles of perceived authenticity and perceived trust. It also investigates whether AI skepticism moderates the relationship between endorser type and perceived authenticity. In a between-subjects experiment, 521 South Korean adults were randomly assigned to view a green advertisement featuring either a human or an AI endorser. The results indicate that endorser type did not directly affect purchase intention. Instead, its influence began with authenticity, which mediated the effect independently and also initiated a sequential pathway through trust. Trust therefore functioned only downstream of authenticity and did not independently mediate the relationship. AI skepticism moderated the effect of endorser type on authenticity, with the human endorser’s authenticity advantage narrowing as skepticism increased. The sequential indirect effect also weakened at higher levels of AI skepticism. These findings position endorser type as a source cue whose influence begins with authenticity judgments and may subsequently extend through trust. The study advances research on AI endorsers and green advertising by identifying the mechanisms and boundary conditions that underlie the effects of endorser type. For practitioners, the findings highlight the importance of substantiating environmental claims and testing AI and human endorsement strategies across relevant audience segments.