The Fateful First Consumer Review

This paper uncovers the striking power of a product’s first consumer review. Our analytical model suggests that two key metrics of online consumer reviews, valence and volume, are not independent, but instead evolve interdependently. This interdependence forms a mechanism to transfer a (dis)advantage from a product’s first review to both a long-lasting (dis)advantage in future word-of-mouth (WOM) valence and an increasing (dis)advantage in future WOM volume. As a result, a single consumer review can significantly influence the fate of a given product. These theoretical predictions, although seemingly unlikely, are supported by our empirical investigations. For example, more than 30% of vacuum cleaner models offered by both Amazon.com and BestBuy.com receive first reviews of opposite valence on the two platforms. Those with a negative first review subsequently suffer a loss in both valence and volume vis-à-vis their counterparts with a positive first review, even after 36 months. More strikingly, the first-review effect on WOM volume increases over time. Our findings reveal a crucial weakness in the user-generated information mechanism. As a consumption-based information source, it creates an information-availability bias such that when a product receives a negative first review, it not only suffers low initial sales, but also loses the opportunity to correct the possible negative bias via subsequent reviews. These findings have substantial implications for online sellers, e-commerce platform providers, and consumers.