“If the player plays more than the CPA paid, the casino wins and the aff loses.
If the player plays less than the CPA paid, the aff wins and the casino loses.”
That’s just anti-mathematical arm-waving. Any sensible person factors that into the CPA calculation. It makes no difference at all whether one person plays a lot, or wins a lot, or whatever.
Every casino knows *exactly* what an average player is worth. They know exactly what an average player from one type of venue is worth compared to another — for instance, a person clicking through from domain1.com might be worth $X on average while players clicking from domain2.com might be worth $Y on average. Which means casinos might gladly pay domain1 $1000 per acquisition while paying domain2 $55.
It should be obvious that no one “loses”, even if you only deliver (or get) one player in your entire life.