The Effect of Word of Mouth on Sales: Online Book Reviews
Chevalier first author. A difference-in-differences across two online booksellers, using relative sales ranks for the same books, found reviews overwhelmingly positive at both sites, with more and longer reviews at one of them, and an improvement in a book's reviews raising its relative sales at that site. For most samples, one-star reviews moved sales more than five-star ones, and review-length data suggest customers read the text rather than only the summary.
Chevalier first author. A difference-in-differences across two online booksellers, using relative sales ranks for the same books, found reviews overwhelmingly positive at both sites, with more and longer reviews at one of them, and an improvement in a book's reviews raising its relative sales at that site. For most samples, one-star reviews moved sales more than five-star ones, and review-length data suggest customers read the text rather than only the summary.
Written from the abstract read 2026-10-18.
What our sources record
Recorded when this source was checked, figures included, with page references and quotation marks removed.
Chevalier, J. A., & Mayzlin, D. (2006). The Effect of Word of Mouth on Sales: Online Book Reviews. Journal of Marketing Research, 43(3), 345-354. doi:10.1509/jmkr.43.3.345.