INFLUENCER MARKETING IN THE PLATFORM ECONOMY: EFFECTS ON CONSUMER TRUST AND PURCHASE DECISIONS

Abstract

The platform economy has reconfigured influencer marketing from a peripheral endorsement tactic into a primary infrastructure of brand–consumer communication, yet academic understanding of how platform-specific algorithmic and architectural affordances interact with source-level and message-level signals to shape consumer trust and purchase decisions remains fragmented. This paper advances a Multilevel Platform–Influencer–Consumer (MPIC) framework that integrates four theoretically complementary lenses—Source Credibility Theory, Parasocial Interaction Theory, the Persuasion Knowledge Model, and Signaling Theory—to explain trust formation and downstream purchase behavior in algorithmically mediated environments. We argue that (i) platform affordances (algorithmic curation, feed-vs.-story formats, ephemerality, comment visibility, and disclosure salience) operate as first-order moderators that condition the activation of credibility cues; (ii) credibility dimensions (expertise, trustworthiness, attractiveness) function as second-order antecedents of parasocial relationship (PSR) strength; and (iii) trust and purchase intention are jointly determined by a dual-route mediation, in which PSR transmits affective commitment while persuasion-knowledge appraisal transmits cognitive skepticism. Synthesizing evidence from three recent meta-analyses (k = 53, 62, and 71 studies), four experimental programs, and emerging virtual-influencer research, we derive a moderated mediation model tested conceptually with reported path coefficients. Results show that credibility → purchase intention is largely indirect (β ≈ 0.18–0.47), that PSR mediates this relationship robustly across platforms, and that disclosure prominence exerts non-monotonic effects conditional on influencer and brand awareness. The study contributes to theory by reconciling contradictory disclosure findings through an attribution-based boundary condition, by formalizing platform affordances as upstream moderators rather than contextual noise, and by extending the model to virtual influencers. Methodologically, we recommend a pre-registered 2 × 3 × 2 factorial design combining behavioral, eye-tracking, and computational-text data. Implications for journal editors, platform governance, and brand managers are discussed.

Keywords: Influencer marketing; platform economy; consumer trust; parasocial relationship; persuasion knowledge; sponsored disclosure; virtual influencers; MPIC framework.