Miles, affiliates need to protect themselves against theft.
I am not saying that your intention is to commit theft, but this business model makes it easy for any casino group to do.
The affiliate brings the player, GP crosspromotes the player to another casino the week after.
Now GP doesn’t have to pay anymore comissions to the affiliate.
Affiliates call this theft.
With such a business model, the only feasible way to go for an affiliate is CPA.