tracking referal field for PPC

I'm trying to promote an Advertisers from CJ through Google Adwords (Content Network), my question is how if it's possible at all should I track where traffic coming from? I've tried replacing Advertiser's link with my own, but all I've got in referal field is Adsense's code, which is google.com, so that didn't really help me at all, is there anything else I can do in order to track or research more? so I can somehow maximize my ROI?