Dartmouth College’s Nailya Ordabayeva and two colleagues—Lisa Cavanaugh and Darren Dahl of the University of British Columbia—showed 300 NFL fans a description of a league-branded hoodie and either a one-star or a five-star review of it by a Cleveland Browns fan. The participants answered questions about their similarity to the reviewer and their interest in buying the garment. When people thought they and the reviewer were alike, their purchase intent was lower if they saw the one-star review rather than the five-star review. But when they felt unlike the reviewer, the one-star review generated significantly higher purchase intent than the five-star review. The conclusion: Negative reviews can boost sales even more than positive ones.

A version of this article appeared in the November–December 2022 issue of Harvard Business Review.