Data warehousing has significantly changed how decision making is supported in organizations. A leading application of data warehousing is customer relationship management (CRM). The power of CRM is illustrated by the experiences at Harrah’s Entertainment, which has assumed a leadership role in the gaming industry through a business strategy that focuses on knowing their customers well, giving them great service, and rewarding their loyalty so that they seek out a Harrah’s casino whenever and wherever they play. In 1993, changing gaming laws allowed Harrah’s to expand into new markets through the building of new properties and the acquisition of other casinos. As management thought about how it could create the greatest value for its shareholders, it was decided that a brand approach should be taken. With this approach, the various casinos would operate in an integrated manner rather than as separate properties. Critical to their strategy was the need to understand and manage relationships with their customers. Harrah’s had to understand where their customers gamed, how often and what games they played, how much they gambled, their profitability, and what offers would entice them to visit a Harrah’s casino. Armed with this information, Harrah’s could better identify specific target customer segments, respond to customers’ preferences, and maximize profitability across the various casinos.