ROI, ASP and other 3 letter words

[trancehead]

Hi,

I am looking for an ASP script that I can use to track my marketing campaigns and ROI. It doesn't need to be very advanced. I just want to know how clicks come through from each advertisor and how many of those clicks buy something.

I could program this myself but don't really have the time.

It would be even better if I could get this script and an affiliate tracking script in one as I imagine they would work in a avery similiar way.

I don't want a hosted solution.

Obviously not having an idea of my ROI is hurting the business right now with misplaced adspend.

Can anybody help?