>Um, don't you think it's a bad idea to call party and ask if an affiliate offering rakeback is legit? I guarantee that Party will respond, "We do not allow our affiliates to offer rakeback."

Actually, you could contact Party to check to see they are an affiliate in good standing without mentioning rakeback.
At least you'd be getting a deal from an established affiliate and not some new guy spamming to get a few players who will disappear soon.

I am thinking references are the way to go, though.