CPA is simply cost per acquisition. You can acquire players via a variety of means that cost differently. There is no reason at all to expect that every acquisiton will cost the same, or even have similar structures. A television commercial on 60 Minutes might yield X customers one week, and 3X the next week due to a more popular segment being aired. No one “loses” when this happens.
Similarly no one “loses” if a casino pays John 35% or $300 CPA, but will only pay Mary 20% or $100 CPA.
This business is just a negotiation. Deals don’t have winners and losers. They just have different terms, based on many factors including the people’s abbility to negotiate.