Although the benefits of the Internet as an additional sales channel to traditional retailers are clear, there are significant variations in the scope and depth of online channel use among retailers. Drawing data from listed retail companies in China, this study examines the impact of online channel use on retailers' performance using event study. The results show that the online channel provides significant improvements in sales, cost, inventory, and return on investments. In addition, we find that the timing of online channel adoption does not have a significant impact on performance improvement, but having a higher local store presence does.