There are thousands upon thousands of potential web destinations for consumers or even those just clicking and wandering through the Internet. Your site needs to provide a reason and incentives for not only business and ecommerce but also just for traffic. Any and all online marketing strategies should begin with the landing page and destination for future consumers and visitors.
The main site you are attempting to drive traffic to (as well as business to) should provide a consumer not only with a reason to visit, but a reason to stay. Successful marketing on the web may get the consumer to the site but engaging content and incentives need to keep them there.
A site needs to have focused direction aimed at a target audience (based on online marketing research). Content that is frequently updated as well as contests, prizes, etc. can keep a consumer coming back to a site on a regular basis.