Referback was one the first lessons i got from this market. It got overpromoted and to new webmasters should be a hard task to earn some money there.
I was sendind a lot of traffic to their sites but no much $$$ back. So, two years ago, i changed their links and things started to improve.
Like professor said, they are online since the early “golden days” of gambling and those guys who sent players to their casinos are enjoying a nice cheque from OUR traffic.
Do you remember when gambling ads were accept in Google and Yahoo? Around 90% of them had links to RB casinos/poker rooms. So, for the USA traffic i think there’s no room for those who started late.
For me, it was the right thing to do. Others can perform better with RB.
They are a great group, but it’s business.