Usability and efficiency are the currency of the popular websites, therefore page download time is critical. The speed at which a page is displayed in a browser window is directly related to its file size, so the drive to minimize the total file of a given page has been fanatically pursued by Web designers. Now that many user have broadband connections, however, it may be tempting to assume that all but the heaviest page will load almost instantaneously. In fact, however, page are increasingly content-rich, and basic 512K broadband link may not perform stunningly. Meanwhile, the number of users with slow dial-up connections may be very significant.