"AdsenseGold is one of a few products that I believe came out scripts produced in a WebmasterWorld discussion (sorry, no link. reg required) where the Google Adsense rep also provided a note that doing this sort of tracking is within the TOS.
As Nick has already said in his post, when you visit his site it is heavy on the hard-sell snake oil but do not let that put you off, the product is ok despite all that.
The product is $97, ignoring the "bonus free gifts" (and you should ignore them), you need to decide if you will gain more than £50 odd that you are spending. Let's dig deep and see what we find."