Valve let's you sell your game on your own website and users can add the key to their steam for 0% skim. 30% rake for what is sold through their ridiculously popular store.

Apple should just charge devs for the services like fee per download if the app is free. I believe currently the minimum paid app is $0.99, so it seems reasonable to allow $.33 apps where the dev gets none and $0 if the dev wants to front the $0.33 per user.

I guess you could argue that even $0.99 apps are subsidized but I doubt it'd be accurate. They already charge to join the dev program and it's not that expensive to run an app store.