Customer Relationship Management (CRM) is a seriously considered issue in today's competitive corporate world. For a firm to maintain an intact relationship with its customers, the vast amount of data within a business enterprise can be refined, mined and analyzed. This paper proposes a decision support system for analyzing and retaining the customers in an online shopping system using various data mining techniques. To achieve successful customer relationship management various mining algorithms for pattern extraction from data have been utilized. Managerial decision makers can make use of these patterns for raising the profit graph of the firm.