Suggestion needed for a Conversion tracking software with Remarketing

Hi There,

I am planning to build a Conversion tracking software, ofcourse its not just another conversion tracker,

It will have some unique features such as:

Remarketing - engage your visitors who did not buy the first time
multi level click conversions (tracks multiple sales or rebuys from the same campaign)
recommendations on improving adwords, yahoo or msn

I would be needing your views on the project and what tool you are using currently?

and what features you want to be implemented?