This study examined how the content and style of online product reviews influence their adoption by consumers. [STUDY 1] analyzed over 700 reviews of Amazon Kindle e-readers to identify factors that increased or decreased review helpfulness. Reviews seen as more helpful used short sentences, provided evidence, discussed multiple product features, and came from experienced users with a positive but not overly emotional tone. [STUDY 2] then experimentally tested these findings. The results provide marketing implications like focusing online messages and identifying influential community members to create more impactful testimonials.