The worst place I know is cryptologic which is crowded with people writing: “GET 25% RAKEBACK AT http://www.xxx.com”
That is incredible but what is more incredible is that I have received an affiliate rakeback request at RoyalCardClub for a huge % for the affiliate.
He stated that he can get lots of players as he has a macro that spam party network chatroom and can;t be stopped. And in top of that he was at the time he emailed me only offering rake back at a Party skin. Of course i declined him but this kind of affiliates exists and some of the poker rooms work with them