Why a human image is better than a human illustration in social media advertising

Retailers rely on human depictions in social media advertising (SMA), yet it remains unclear how different forms of human representation shape consumer responses. In particular, brands frequently choose between real human images and human illustrations, despite limited empirical guidance on the consequences of this choice. This study examines how using a human image (vs. a human illustration) influences key emotional responses (interest and enjoyment) and credibility perceptions (attractiveness and trustworthiness), and how these ad-triggered responses subsequently affect attitudes toward the ad and brand, as well as purchase behavior. Across five studies (one pre-study, three experiments, and one ad-based survey; total N = 1210), we demonstrate that a human image in SMA generates greater interest and credibility than a human illustration, whereas the latter produces higher levels of enjoyment. Moreover, we document that both enjoyment and trustworthiness mediate the paths from ad type to attitudes toward the ad and brand, while interest and attractiveness solely mediate the relationship between ad type and attitudes toward the ad. Lastly, we reveal that customers’ interest and trustworthiness predominantly enhance purchase intention and that human-image-based ads (compared to human-illustration ones) not only augment purchase intention but also translate it into actual buying behavior. Based on these findings, we identify the optimal situations for using each type of advertising and offer strategic insights for designing more effective and profitable SMA.