Are many too much? Examining the effects of multiple influencer endorsements from a persuasion knowledge model perspective

Advertisers report avoiding collaborations with influencers who endorse a large number of brands because they fear the negative outcomes of such over-endorsements. Yet many popular influencers endorse far more than one brand. Earlier research on multiple endorsements by celebrity testimonials and their effects on both brand and endorser evaluations produced mixed results. This article investigates the consequences of multiple endorsements in an influencer context. We conducted a between-subjects online experiment in which we varied the number of brand endorsements (one, three, seven endorsements) presented by an influencer. Results show that multiple influencer endorsements affect the performance of evaluative persuasion knowledge and subsequent coping behaviors, which in turn negatively affect brand attitude and perceived influencer authenticity. Coping with influencer endorsements is generally moderated by participants’ parasocial relationships with the influencer. However, parasocial relationships appear not to be relevant in specifically processing multiple endorsements. Based on these findings, we discuss theoretical implications for researching influencer marketing from a persuasion knowledge model (PKM) perspective.