When less is more: the interactive effects of influencer popularity and product involvement on consumer attitudes

Purpose With the rapid growth of influencer marketing, whether influencer popularity consistently enhances consumer attitudes remains unclear. Drawing on the elaboration likelihood model (ELM), this study adopts a product involvement perspective to examine the effect of influencer popularity on consumer attitudes and the conditional role of perceived authenticity. Design/methodology/approach Two online experiments were conducted. Study 1 examined the interaction between influencer popularity and product involvement. Study 2 employed a 2 × 2 between-subjects de-sign, manipulating both influencer popularity and product involvement, and tested the mediating role of perceived authenticity using moderated mediation analysis. Findings The results indicate that the effect of influencer popularity is contingent on the level of product involvement. However, the specific direction of this effect under low involvement varies across the two studies. Further analyses suggest that perceived authenticity may serve as a conditional mechanism, with its role becoming more salient under high involvement and substantially weaker under low involvement. Originality/value This study extends existing ELM-based reasoning to the influencer marketing context by identifying product involvement as a boundary condition associated with influencer popularity effects and perceived authenticity as a conditional mechanism under higher involvement. By integrating influencer popularity, product involvement, and perceived authenticity within a unified framework, the study provides a more context-specific understanding of influencer effectiveness.