Expertise Makes Perfect: How the Variance of a Reviewer's Historical Ratings Influences the Persuasiveness of Online Reviews

Online reviews have become an important source of information for consumers’ purchase decisions. Drawing upon the consumer expertise and persuasion literature, this study proposes that consumers are more willing to accept a reviewer's recommendation when his/her historical ratings in a certain product domain display greater variance. Five experiments provide consistent support for this hypothesis and the underlying process. Study 1 tests the proposed effect of a reviewer's rating variance on consumers’ willingness to accept the reviewer's recommendation. Studies 2 and 3 show that this effect can be attributed to perceptions regarding the reviewer's expertise. Moreover, this “variance-expert inference” effect is attenuated when the consumption experience of the reviewer is limited (Study 4) and when the consumers are familiar with the products (Study 5). The theoretical implications for the online review and persuasion literature and practical implications for online retailers are discussed.