The Effects of Influencer Types and Sponsorship Disclosure in Instagram Sponsored Posts

Abstract Brands and digital marketing rely on influencers more than ever. As the marketing landscape for social media influencers quickly changes, policies and regulations require standardized sponsorship disclosures. This study examined the effectiveness of three different types of sponsorship disclosure—no disclosure, implicit disclosure, and explicit (standardized) disclosure. This study also compared three different types of influencers and their effectiveness as endorsers: a celebrity, a micro-influencer, and a layperson. The results of an online experiment showed that the presence of sponsorship disclosure and explicit disclosure successfully activated consumers’ conceptual persuasion knowledge, which leads to diminished message credibility, engagement, product attitude, and purchase intention. Furthermore, the results show that a layperson is the most influential endorser; celebrities and micro-celebrities were indifferent as influencers.