“why would an affiliate approve the self-advertising of online casinos?”
Why wouldn’t one? Casinos do it all the time.
“What are we going to eat – rats?”
If you suck at promoting stuff, then you might.
A casino has no edge in creating a portal over anyone else. An issue does arise if they *do* give themselves an edge, like linking from the casino to the portal. If somebigcasino.com wants to make a portal that beats me in the rankings, that is no different than if Randy or the Professor or John Kerry does it.
Casinos will pay to get players sent to them. That isn’t going to change, regardless of how many players a casino generates on its own via portals, TV, boxer spraypainting or anything else.