Need to track affiliate transactions for wp created SID'S

Ok, I want to track custom affiliate link sid's that are created in wp, not in the affiliate marketplace. So for example if I add a term to the affiliate link , I can automatically see the transactions made on that new tracking link. How can this work since I'm adding tracking via a 3rd party ( wp)?.

So far I'm looking at the Google Analytics for Wordpress plugin which doesn't seem to show earnings, and Linktrackr.
Joomla has a similar plugin.