Influencer Marketing on Instagram: Empirical Research on Social Media Engagement with Sponsored Posts

Abstract

While sponsored posts by social media influencers (SMIs) on Instagram have dramatically increased as an advertising strategy, empirical results on their efficiency have yet to emerge. These sponsored posts are placed next to nonsponsored posts (NSPs) on SMIs’ Instagram profiles. In the current study, we investigate how consumers engage with sponsored posts compared to NSPs and how engagement varies when such are posted by microinfluencers compared to macroinfluencers. Moreover, we explore engagement with sponsored posts containing different advertising appeals based on the advertising strategy, which determines whether sponsored posts contain appeals based on factual and rational information (i.e., informational appeals) or emotional and personal information (i.e., transformational appeals). Using a binomial regression on a unique data set of 64,438 sponsored Instagram posts by SMIs, we show that (1) users engage more with sponsored compared to NSPs, (2) particularly by microinfluencers, and (3) users engage more with sponsored posts with informational appeals by macroinfluencers than by microinfluencers. These findings provide meaningful insights for both advertisers interested in employing influencer marketing and SMIs interested in cooperating with advertisers for sponsored posts; the findings also advance the literature on influencer advertising and marketing.