TikTok influencer ad disclosure types on consumer trust

Abstract

This thesis examines how TikTok influencer sponsorship disclosures affect consumer trust, using engagement as a proxy. Drawing from existing works like the Persuasion Knowledge Model, Parasocial Interaction Theory, and the Authenticity Management Framework, this study analyses 2,250 TikTok posts across 45 beauty influencers with both WEKA machine learning models and JASP regressions. The results affirm that visible sponsorship does have a trust penalty, indicated by a drop in engagement, on TikTok posts. In terms of commercial cues beyond traditional sponsorship, it could not be concluded that explicit disclosure of free PR products impacted engagement, ambiguous disclosure of free PR products reduced engagement, and affiliate codes increased engagement. This suggests that economic incentives can boost perceived value to viewers and drive interest rather than diminish authenticity and trust. Regarding different clarity tiers for different disclosure types (low, medium, high), there is a directional trend toward greater engagement penalties, but statistical evidence remains inconclusive due to multicollinearity within the disclosure tiers. Additionally, although it is shown that a positive general tone increases engagement overall for beauty influencers on TikTok, it does not moderate the engagement penalty of sponsorship. Thus, the results indicate that a generally positive product review tone across an influencer’s content and sponsorship effects work additively rather than interactively. Overall, these findings expand previous social media influencer ad research into TikTok and highlight the importance of transparent and consistent disclosure practices, clarify how different commercial cues impact how audiences respond to influencer marketing, and provide guidance for influencers, brands, and platforms navigating the ethical and regulatory expectations associated with social media advertising.