Effects of celebrity, social media influencer, and peer endorsements on consumer responses toward a celebrity-owned brand: the role of source credibility and congruency

Considering the growing popularity of celebrity-owned brands through social media advertising, this study investigates how different types of product endorsers [i.e., celebrities, social media influencers (SMI) and peer internet users] influence consumers' judgements toward celebrity-owned brands on Instagram. Results indicated that perceived expertise was important in consumers' evaluation of product endorsement messages, whereas perceptions of endorsers' trustworthiness did not differ across the three conditions. In terms of endorsement effectiveness, celebrities and SMIs had more significant impacts on consumer responses than fellow consumers when endorsing a brand owned by the celebrity, in which perceived expertise mediated the relationship between endorser type and advertising effectiveness. In addition, the endorser-consumer congruency is more prominent to SMI endorsements than to peer endorsements, whereas the endorser-product congruency is more crucial to peer endorsements than to celebrity endorsements. Theoretical and practical implications for researchers and marketers are discussed.