Influencer marketing effectiveness: the mechanisms that matter

Purpose - The continued evolution of influencer marketing has created a need to better understand influencer marketing effectiveness. With brands increasingly partnering with influencers, research is yet to provide an integrated perspective examining the critical role of both parties. This study aims to draw on the source credibility model and signaling theory to explain the mechanisms that matter in influencer marketing effectiveness. Design/methodology/approach - The proposed model of influencer marketing effectiveness is analyzed using partial least squares with data from 281 followers of social media influencers. Findings - The authors establish influencer characteristics of popularity and attractiveness as heuristic cues that inform judgments of influencer efficacy. Further, category involvement and altruistic motives for collaboration are shown to moderate followers' reliance on these heuristic cues. Then, a sequential mediating effect demonstrates the critical roles of the influencer and partner brand in three desired outcomes: enhanced perception of brand authenticity, enhanced brand engagement and positive attitudes toward influencer posts. Research limitations/implications - Future research should consider other heuristic cues that could inform influencer efficacy judgments and switch the focus toward the partner brand's impact on such judgments. Practical implications - A step-by-step visual framework is presented to help marketers and influencers translate these findings into key responsibilities for developing more effective and collaborative partnerships. Originality/value - Besides presenting an integrated perspective, signaling theory provides an original lens for explaining influencer marketing effectiveness, addressing the need to expand the theoretical boundaries of influencer marketing research.