Agree with Jinn.
The casinos are more than savvy when it comes to CPA. If it doesn't pay what they expect you will probably end up out of pocket yourself. The reputable casinos will almost invariably attach a minimum deposit amount to any player acquired on CPA and those that don't will probably just rip you off.
I'd never touch CPA myself if the option of Revshare is there: for that reason of course, plus there are 2 other major issues. Firstly, if you lose your traffic temporarily (hammered by Google etc), your revenue dries up there and then. You're screwed until you get your traffic back.
Secondly, finding the balance where both you and the casino are happy with the deal is very hard. If
they are happy and keep extending, it probably means they got you on the cheap and you will invariably ask for more. If
you are happy, they are probably thinking the deal is too weighted in your favour and will start to make the deal harder to achieve or pay you less.
The upshot of all that is that you have a relationship that is not mutually beneficial but in opposition. Consequently trust is harder to come by and trusting, mutually beneficial relationships are the key to success in ANY business.
I could go on and on about that: why you should never dispute on public forums, why you need to compromise on deals instead of going for the highest rates, etc etc, but I'll spare you
