I think part of the problem here is that Apple's 30% fee is clearly aimed at digital goods for which the marginal sale has approximately no costs. Most digital

I think part of the problem here is that Apple's 30% fee is clearly aimed at digital goods for which the marginal sale has approximately no costs. Most digital goods are quite scaleable, and have enormous marginal per unit. However, Spotify is not at all like that. Neither is Kindle, neither is Netflix. So a system that is somewhat justifiable for software is simply insane for digital goods which do have marginal costs to sell. This is not necessarily simply to resolve. Witness, for example, the troubles with corporate taxation, and EU proposals for a digital tax on gross revenues rather than net revenues. This is basically aimed at the same sort of problem. E.g. Spotify might actually be very happy to hand over 30% of profit per user to apple, as opposed to revenue per user. But, how the devil do you calculate that simply, for all companies in this category? I don't know exactly how to address it, but Apple should in some way address the fact that not all digital goods have zero marginal costs to sell. This is far from the only issue at play, but I haven't seen it addressed, and I think it's fairly central.