To support online customers to make better purchase decisions and promote sales，online shopping websites often encourage customers to post product reviews by providing different incentives ( e． g． ，small economic rewards) ． But how economic rewards affect online product reviews is still an unanswered question．Based on theories of social relations，this empirical study investigates the effects of economic rewards on online reviews by using data from two popular B2C websites in China ( jd． com and amazon． cn) ． The results show that compared with social rewards，economic rewards may lead consumers to post online reviews with higher review rating but lower review depth and less review helpfulness．