The Effects of Comparative Reviews on Product Sales

Consumers increasingly rely on online reviews to make their purchase decisions. Drawing from linguistics and sociology research, the authors posit that comparative reviews, which highlight the similarities and differences between a focal product and its alternatives, may influence consumers' regulation systems and perceived credibility, thereby affecting product sales. The authors examined 61,480 reviews on e-commerce platforms to explore the effects of comparative reviews and their valence on product sales. By using a supervised learning approach, they identified positive and negative comparative reviews, as well as positive and negative regular reviews, and then applied a two-way fixed-effects model. The results show that comparative reviews positively impacted product sales. Specifically, positive comparative reviews had a greater effect than positive regular reviews, whereas negative comparative reviews had a lesser absolute effect than negative regular reviews on product sales. Moreover, positive comparative reviews exerted a greater absolute effect than negative ones. A follow-up controlled lab study further substantiated the authors' results and insights. The findings offer new insights and practical guidance for marketers and practitioners in promoting more comparative review posts and optimizing online review presentations.