Impartial endorsements: Influencer and celebrity declarations of non-sponsorship and honesty

Abstract Effects of sponsorship disclosures on Instagram and other social media have been experimentally tested in advertising research, but effects of impartiality claims are relatively unknown. In this study, we built on two previous experiments that tested effects of claiming non-sponsorship or “honest opinions.” In addition to testing these in conjunction, we examine the potential for order effects of claims, and differences between celebrities and influencers. How do impartiality claims about brand-focused social media posts influence persuasion knowledge, credibility, intentions to engage with the message, attitudes, and purchase intentions? This manuscript reports findings from 287 women students in the U.S. who participated in a within-subjects experiment. We observed that posts claiming non-sponsorship were perceived as less likely to be advertisements or have selling intention. These non-sponsorship claims also enhanced trustworthiness. Honesty claims enhanced expertise. Honesty and non-sponsorship worked together to boost trustworthiness, expertise, attitudes, and purchase intentions, yet messages with no claims at all yielded the most positive attitudes and intentions. This illustrates that impartiality claims work better together than in isolation. Impartiality claims performed similarly for influencers and celebrities. Presenting impartiality claims at the beginning of a post aided ad recognition but reduced intentions to share or follow a source.