Tracking affiliates by Url to publisher and or website.

I want to know is there a way in the programming world that dev-archive's or web devs do to know who thier competition is.By tracking and identifying theier true URL and or domain name.
Tracking it back to the affilliate it came from or publisher of the tracking cookie they provide.
Or would it be identifiable in the source code.

Has this thread been questioned before, and is it at all possible to retrieve or parse this information.
If anyone know please post it. here with a reply.

Thank you.
Gmatter