Karon Thackston has a great article on how to make your site the one the shopper will pick to buy from.

"When you arrive, everything looks almost the same except the logo. Same navigation, same links, same inventory, same prices. The shipping amount is the same, and the delivery policy is identical to the site you just came from. As you click from site to site, it's like déjà vu. How are you supposed to make a decision to buy when all your options are equal? What will be the determining factor between site A and site B?"

Catch it @ http://www.smallbusinessbrief.com/articles/copywriting_and_website_content/005125.html