Don't they skim like 30% or something crazy like that off the top of every purchase? If so, I wouldn't call it "solved".
When you consider the infrastructure provided for hosting, payment processing, distribution, and the storefront itself, 30% is not unreasonable.
That 30% is on more than $60B/yr for apple. Are you suggesting that their overhead for running app store is anywhere within even a couple orders of magnitude of $20B/yr?
I'm suggesting that, compared to what you'd pay to do these things for yourself, 30% is a steal. There's a reason people are ok with paying it.
Kinda/sorta/not really. It's why "free to play"/in-app-purchases rather than up-front-buying is such a big (and annoying) trend.
Not micro in the sense of penny transactions.
They don't lump together small in-app payments, so you get billed only larger amounts?