How businesses resolve customer-complaining behavior effectively has been considered a "defensive marketing" strategy or a "zero-defections" 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 (electronic customer relationship management). 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. 1000 customer complaints from three different publicized e-business customer service centers and 500 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 quickly 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.