[chipotle_coyote]

I think you just solved a conundrum I was having thinking about this very question -- a video class that you watch in an app is in a sense a purely in-app digital good, and Apple appears to have recently been getting super-aggressive about interpreting it that way. But "not a purely digital good" is a great delineation, and one that Apple should probably be making.

(I'm not arguing that Apple's 30% cut requirement for even purely digital goods is appropriate; I think Ben Thompson's recent suggestion of a difference between goods with marginal costs vs. zero-marginal costs goods would be a better starting point, if there were a way to express it simply. Of course, a better suggestion might just be for Apple to allow developers to integrate their own in-app purchase systems for goods and services that aren't explicitly tied to the Apple ecosystem and use non-Apple infrastructure for delivery -- not just video classes but Netflix subscriptions, Kindle books, and so on.)