[gamble]

Because radio is not a substitute for recorded music. The inability to choose what you're listening to was always the stick that compelled listeners to purchase a recording. If you have Spotify, there is no reason to ever purchase that music in a download store.

[lukifer]

Fast, reliable, and unmetered wireless is by no means ubiquitous. There is still the benefit of being able to play offline, burn to CD for the car, share with friends, etc.

Admittedly, the incentive to want offline music may continue to diminish over time.

[k-mcgrady]

Spotify offers offline access of their $10 p/m plan.

[lukifer]

Ah, didn't know that. Guessing they don't allow CD burning, but I imagine that's a dwindling use case.

[stdbrouw]

Well, more importantly, they don't allow sharing. You can have it offline but it's not like they're giving you plain mp3's to do with what you please.