A cookies is a tool used by a Web site to store information about a user. When a visitor enters a Web site, the sends a small text file(the cookie) to the user's computer so that information from the site can be loaded more quickly on future visits. The cookie can contain any information desired by the Web site designers, including customer number, pages visited, products examined, and other detailed information about the behavior of the consumer at the site. Cookies are useful to consumers because the Web site will recognize returning patrons and not ask them to register again. Cookies are also used by advertisers to ensure visitors do not receive the same advertisements repeatedly. Cookies can also help personalize a Web site by allowing the site to recognize returning customers and make special offers to them based on their past behavior at the site. Cookies allow Web marketers to customize products and segment markets-the ability to change the product or the price based on prior consumer information (described more fully in later chapters). As we will discuss throughout the book, cookies also can pose a threat to consumer privacy, and at times they are bothersome. Many people clear their cookies at the end of every day. Some disable them entirely using tools built into most browsers.