Exactly. And iTunes worked for three reasons: (1) it's a single player experience; (2) the iPod; (3) DRM lock-in (there is no longer lock-in, but only for song

Exactly. And iTunes worked for three reasons: (1) it's a single player experience; (2) the iPod; (3) DRM lock-in (there is no longer lock-in, but only for songs purchased after the date lock-in was expired. iTunes Match was a service added to maintain lock-in after DRM-free music was announced.)