Faces matter

Using field and survey experiments, we examine how product reviewers' facial profile images influence behaviour on e-commerce platforms. Across a series of studies, we show that facial profile images accompanying positive reviews, relative to system default images, increase purchase conversion rates by 6.98% on average (Study 1). Evidence from a controlled survey experiment suggests this operates through a causal effect of faces on perceived review trustworthiness (Study 3). The effect is unlikely to reflect specific facial traits or expressions, which were not clearly discernible. We further demonstrate that the observed effects are not explained by profile personalisation alone (Studies 2 and 3). As an additional explanation for the face effect, we find that users who upload facial profile images may write more helpful reviews (Study 4). Overall, our findings show that human faces can uniquely and meaningfully promote the perceived trustworthiness of online information, contributing to research on face effects, trust, and e-commerce.