[awake]

I love this question. It’s plausible enough to imagine Apple charging for ads. But the implications are huge. Imagine every hardware platform charging for transactions made on that platform. It would be like landlords getting a flat percentage of your income on top of an annual fee.

[plexicle]

It would instantly tank a lot of huge apps/industries. Especially ones with razor thin margins already.

Consider stock trading apps/fees, for one random example at the top of my head.

[ballenf]

It would be more like rent is free if you're unemployed, otherwise x% of your income.

[Nasrudith]

It doesn't work for both the same reason as the example. Everyone who would be advantaged would leave to the one which doesn't charge fees based on something irrelevant to operation.