Too good to be true: The role of online reviews’ features in probability to buy

Online consumer reviews are broadly believed to be a necessary and powerful marketing tool, and as such they have attracted considerable attention from both marketers and academics. However, previous research has not sufficiently focused on the effects of various review features on sales but rather used proxy measures such as consumers’ purchase intention or perceived helpfulness of reviews. Hence, the aim of this study was to investigate the effect of review valence and volume on actual sales. We use data from three different e-commerce websites and study light bulbs, women’s athletic shoes, natural hair care products, and herbal vitamins. The results show that, contrary to popular belief, more positive ratings do not simply result in higher sales. We find that the effect can be nonlinear, where the probability of purchase increases with rating to about 4.2–4.5 stars, but then decreases. Also, although the majority of extant research suggests that larger numbers of reviews bring more positive outcomes, we show that it is not always the case.