e easiest place to start is with the World Wide Web, or "the Web," as it is most commonly known. Companies, whether they are "dot-coms" or more traditional businesses - often called "brick and mortar companies" - have used the Web in some straightforward ways thus far. Most traditional companies have built Websites designed to reinforce their brand, explain their business, and describe how they differentiate themselves from their competition. Companies also identify their management, provide overviews of their products and services, provide directions to their headquarters, and other fundamental information. These sites typically offer very little in the way of customized information and are often developed as a first step towards a more significant Web presence. Many companies have moved beyond the initial stages and are building sites that provide a broader range of products and services. For example, online publications provide subscription-based services and access to research information. "E-tailers" provide online shopping of all kinds. Banks and other financial institutions provide everything from online balance information to bill payment and consolidation and wealth management. Insurance companies provide quotes and even sell policies online, and the list goes on. These companies are finding that the Web, when used correctly, is perhaps their best tool for serving and retaining customers; hence, the term eCRM, or e-Customer Relationship Management. Recognizing this, savvy service providers have placed more emphasis on providing customized information and navigation tools to the user. In other words, the user can dictate to some extent what services and information a Web site will provide and how it will be displayed. A basic theory behind eCRM is that customers are more likely to use a site and stay with a specific provider if they feel their needs are being addressed individually and that they are afforded a high level of control over the Web. Providers that focus their services on multi-tenant building