but they will generate advertising revenue for Apple. Just like the developer gets cut of the advertising so does Apple. The developer isn't paying but the advertisers certainly are.
How do you figure? 100% of in-app advertising goes to the split between the ad provider and the developer. Apple doesn't get 1 cent from that (unless the ad comes from Apple, obviously).
It's a loop. The ads don't make Apple money but they market games that profit off in app purchases. Apple gets 30% of those purchases so is incentivized to enable these ads and participate in making them more effective like providing metrics.
Apple gets a cut of a Google ad in an iOS app?
Its not advertising revenue unless the revenue is generated by selling advertising.