You're right, Einstein, big corporations that make large sums of money never do anything corrupt in order to eek out that last couple of dollars when they don't really need to.
No online site has any incentive to ensure future business from idiots that shouldn't be there in the first place. That's a ludicrous idea. I mean, it happens every day in the real world, Enron, Toys R Us, etc. There's never an incentive to lie, cheat and steal, yet it happens constantly. So, to say there is no incentive is, well, dense.
You play at certain sites, and not others, why? Because you feel that the games are easier at site A than at site B. In order to maximize profits a site needs more customers, both donkeys and good players, which, I will give you the benefit of the doubt that you are since you are here. So, they do have an incentive to make sure there are fish there so you will play at their site. The more players, the more they make.