A Google Groups thread discusses a classic SEO challenge, passing link popularity for tracking URLs. Honestly, I cannot sum up the issue better than the original poster:
Our site uses query string variables in our URL's to track traffic and internal vist patterns. As an example our email offers our external ads will use a URL similar to: www.website.com/shop/scarfs.asp?cpn=bbl2345And then upon entering the website they might click on internal links like: www.website.com/shop/scarfs.asp?sc=2332
Those Variables have the capability to combine: www.website.com/shop/scarfs.asp?cpn=bbl2345&sc=2332
Over time this has created millions of variables in Google's index.
How can this webmaster keep the tracking capabilities but at the same time, keep the link popularity to the main URL?
With Yahoo, they give you a tool within Site Explorer named Dynamic URL Rewriting. This tool allows you to tell Yahoo that these dynamic URLs really refer back to this main URL. You really do not have to do any coding on your site or server to communicate this to Yahoo. All you do it plug in the information into Yahoo.
With Google, it is not that easy. In Google, you need to make sure you set up your site and server to communicate this to GoogleBot. JohnMu, a Googler explain:
Assuming you want to keep track of those numbers, move them to a cookie and out of the URL. If you can do that, you could 301 redirect from the tagged URL (with the numbers) to a clean URL while setting a cookie on the user's side. In other words, everyone is redirected to the clean URLs and users can still be tracked appropriately. Of course, this involves changing a bit on the server side -- and depending on how much time you have it might be hard to get done anytime soon...
There are other solutions, but they don't work as well as this one.
Forum discussion at Google Groups.