How businesses resolve customer complaining behavior effectively has been considered a "defensive marketing" strategy or a irzero-defectionsl. strategy, which diminishes customer dissatisfaction. Handling customer dissatisfaction accompanies Web customer complaint management, which might be the critical issue for online customer service solutions and e-CRM. In this paper, the authors 1) investigate the current sources and causes of online complaints; 2) seek effective ways of handling customer complaints by examining different product types; and 3) provide guidelines for successful e-CRM. One thousand customer complaints from three different publicized e-business customer service centers and five hundred complaints from online feedback systems were analyzed in this study. The research findings suggest that e-businesses should 1) provide excellent online customer services because customer service is the most important factor in online customer satisfaction; 2) respond to customers' requests/complaints fast because the response speed is more important in online customer satisfaction than offline; and 3) employ strategies that are appropriate for the product category in question.