[eloisant]

Behaving like a USB key is not a simpler mental model than "buy books on Amazon and they're on your device".

I agree on the freedom for geeks, but let's not fool ourselves into thinking non IT experts want to deal with files.

[goosedragons]

Kobo has the same thing. Buy books on Kobo and they are on your device. But they also support ePub natively and ADE DRM natively so there's more options of where to source books before conversion.