As any marketer knows, a database of names and contact information is one of your most valuable assets. To build your own e-database, which consists of your Web site's visitors' e-mail addresses and demographic data about them, encourage them to become " members" of your site. Why would someone become a member of your site? Offer membership for free, then give members special access to additional information and resources on your site that are truly useful. They'll "pay" you by providing you with their personal data, which you can use to better serve them or sell your products or services to them.