You'll have to give your visitors something to motivate their return - some content that will wet their appetite and keep them coming back for more. Provide a library of free ebooks ready to download. Give visitors a free autoresponder marketing report. Feature a shareware program of the week with review. This explains the popularity of the numerous contest sites available on the Net.
Winners get prizes like computers, cars, cash, and more.
For a small fee you can host one of these contests on your site. You'll get repeat traffic and a copy of each entry's contact information. This is a great resource for building a customer list. You see for those who invest the time a discussion board can be a tremendous draw for repeat visitors. The benefit is that your visitors will begin to develop a sense of community around your site.