I have manged to get our data feed solution running pretty smoothly now, so I'm looking to add some extra features for our affiliates.

One of these features I want to add is tracking product views, but I see two ways of doing it. I can either change the image link to a dynamic url that will record the product image being viewed. Or, I can add a seperate tracking image column to the feed.

My question is, what do affiliates prefer to use? I would also like to know what type of statistics are most useful to affiliates. Is the CTR for individual products useful? Should I include view tracking on the thumbnail images, and also provide a seperate tracking image so affiliates can track which products get clicked on for the full info page, or is that something affiliates should be doing with their own internal site stats?

Any advice or discussion would be much appreciated.