Your reasoning is partly correct. The reason CPA is so bad is because it unfairly treats one of the parties in the business relationship. On one side, a bad affiliate sends a lot of bonus abusers and such while getting a CPA on each player, which the casino doesn’t appreciate and therefore closes down your account, maybe even withholding payment. On the other side a good affiliate sends quality traffic and those players produce way more over time than the CPA amount, resulting in the affiliate missing out on potential revenue. In either case, the affiliate looses.