[tag-tec]Google[/tag-tac] has a beta service out called Web Optimizer. It looks at your site and tells you what’s working and what’s not for monetization and other things.
From Google:
“Use Website Optimizer to test different website content. Graphical reports show which content engages your audience and results in the highest conversions. Run that content to improve your users’ experience and convert visitors to customers. Complete the steps below and sign-up to participate in our beta test.”
The program is in beta so you’ll have to take it as-is. But every beta I have used on Google has been pretty tight right out of the gate.