I don't think that's actually what's happening with that. ref=nosim is an old thing (no longer necessary) for going to the product page directly. I can't see an

I don't think that's actually what's happening with that. ref=nosim is an old thing (no longer necessary) for going to the product page directly. I can't see any tracking that they can do with a URL component that they wouldn't have anyway (e.g., knowing the referrer, IP etc.)