Impact of Follower Count and “Common Friends” on the Advertising Effectiveness of PR Posts:

The aim of this study is to examine the effects of influencer follower count and the presence of “common friends” on advertising effectiveness in PR posts. Previous research has shown that influencer marketing generates a greater advertising effect compared to celebrity endorsements, with follower count being a key factor. While prior studies have focused on quantitative aspects such as follower count, qualitative factors such as follower relationships have received less attention. This study examines the impact of Instagram’s “common friends” feature on advertising attitude and purchase intention. In Experiment 1, we found that PR posts with more followers of the influencer had significantly higher advertising attitudes and purchase intentions than PR posts with fewer followers. In Experiment 2, common friends were displayed, unlike in Experiment 1, and then PR posts by influencers with a small number of followers were found to have significantly higher advertising attitudes and purchase intentions than PR posts by influencers with a large number of followers.