There was an article posted recently on eCommerceGuide.com (http://www.ecommerce-guide.com/solut...le.php/3670556) that talks about the success of using Comparison Shopping Sites. It was a good article, but one key point that I think was missed is the trend toward vertical search and the emergence of vertically focused CSEs.

The most notable example of this is cNet Shopper, but others exist. Another good one to take a look at is Builders Square. They've taken a Home & Garden / Home Improvement focused approach to the CSE model and I would expect that conversion rates are much higher when working with vertically focused CSEs.