Appending parameters to affiliate urls

I am currently looking for a script that can append a parameter (keyword, medium, source) dynamically using cookies to the end of my CJ, Linkshare, and Performics affiliate links (sid=,mid=,u1=)

It would be really nice, if it were possible to append a whole referring url to the end of the affiliate links. I am about to hunt down a few programmers on some of the freelance boards, but thought I would drop by and see if anyone knew how to do this and if there was a free script out there that would accomplish this feat.

Whatever you do, make sure that those alternative URLs cannot ever be indexed by search engines.

If they ever do get indexed then you will cause yourself a huge "duplicate content" problem.

Also many merchants don't give any credit to affiliate links indexed in search engines.

Actually, those affiliate links should be set up so that they redirect to the merchant's home page via a 301 Permanent Redirect. That way the merchant can get credit for all the links.

There are many merchants who have been very successful with this method of affiliate marketing.