I'd like to see it done 'in house'. More and more small businesses are entering the market - kitchen table admins without the expertise nor the time to deal with adding code to a page. For some, an Excel spreadsheet is over their heads. ebay is on it's way out in favor of easy to use carts. Many merchants are finding that thier own cart-site is cheaper to run.
The cart that has the fewest hassles with the fewest hotfixes and the most admin-friendly features will sell best.
Should be a simple matter of getting a list of product pages from your host and then listing the products and the # of times they were looked at by shoppers.
Have a look:
http://publib.boulder.ib...oc/concepts/cazbarpt.htmWebSphere Commerce Analyzer business analysis reports
Business analysis reports contain information about
 products displayed and sold, and customer loyalty. This category includes the following reports:
Products looked at least 
Products looked at most 
Products added to shopping cart least 
Products added to the shopping cart most 
Products looked at by a single user 
Products looked at by age 
Products looked at by income 
Products looked at by marital status 
Products looked at by gender 
Most loyal customers 
Loyal customer product 
Browser buyer conversion ratio 
Cross-sell Up-sell 
There is a way to do this.....