Reviews and reputation · Longitudinal observational analysis of review and sales data
The Effect of Word of Mouth on Sales: Online Book Reviews
Chevalier, J. A., & Mayzlin, D. (2006). Journal of Marketing Research, 43(3), 345–354.
Plain-English take
An improvement in a book's reviews increased its relative sales at that site. For your marketing: This is a foundational example of why negative feedback may carry asymmetric weight and why review text can matter.
How much weight to give this
3.0/5 Limited or context-dependent evidence
The 1–5 evidence-check score is a practical reading aid, not a formal peer review or a probability that a conclusion is true. It combines design strength (2 points), sample reporting (1), comparison/control clarity (1), and how much of the paper could be checked (1). Access affects how confidently this directory can assess a study, not the study's underlying quality. Blinding is reported separately because it is not relevant to every design.
This is observational evidence; selection or unmeasured differences may affect the result.
A usable sample size is not stated in the profile's accessible source.
Statistical adjustment is not the same as random assignment; review the controls and assumptions.
An accessible full paper or manuscript is linked, making methods easier to check.
Double-blind? Not applicable in the same way as a participant-treatment experiment.
Research question
What the authors investigated
Do online consumer reviews affect relative book sales at competing retailers?
Design
Longitudinal analysis of book reviews and relative sales at Amazon and Barnes & Noble, using differences across sites and over time.
Sample and setting
Books sold on Amazon.com and Barnesandnoble.com; the publisher abstract does not state the number of titles.
Reported result
What the study found
An improvement in a book's reviews increased its relative sales at that site. In most samples, the impact of one-star reviews was greater than that of five-star reviews; review-length patterns suggested readers used review text, not just summary ratings.
This is a paraphrase of the source. Check the original paper for definitions, estimates, statistical uncertainty and analysis details.
Scope and transfer
Limitations to keep in view
The setting is books and retailer-specific review ecosystems. The publisher abstract provides limited design details, and the working paper predates the final journal publication.
Possible founder application
A foundational example of why negative feedback may carry asymmetric weight and why review text can matter. SaaS buyers and review platforms differ, so test the effect on your own category and conversion path.
Evidence access
Publisher abstract and open earlier working-paper version
SAGE publisher abstract and NBER working-paper record retrieved with Firecrawl; the open link is an earlier working-paper version.
If only an abstract or metadata was available, the profile is limited to claims supported there. A paper's paywall does not change its evidentiary status, but it limits what we can substantiate from accessible text.