We investigate how a seemly-unbiased reward-for-feedback mechanism affect both consumers and sellers’ behavior in online market, more specifically, how a seller applies it to manage his reputation as well as to signal his quality, and what are buyers’ responses to it. Furthermore, we examine whether the monetary reward bias the nature of feedback. Using a data set collected from September 2012 to February 2013 in Alibaba’s C2C market place, that implemented a “reward-for-feedback” mechanism in March 2012, we implement a “quasi-experiment” identification strategy and find that a seller is more likely to choose the “rebate-for-feedback” option in his earlier stage. Experienced sellers are more likely to choose the rebate option, and experienced buyers are more likely to get rewards. Sales of an item is higher when the seller chooses the rebate option. What is more, rewards induce buyers to write more detailed feedback but not biased toward positive feedback.