This is a Pandora-like service. You don't get to pick the songs played, just the artist/genre/song that the streaming service's playlist will use as a reference point.

I liked the concept when Pandora was new, but it seems somewhat out dated in a world of Spotify and Rdio which has radio features as a subset of a product that allows more user choice alongside passive discovery. A Pandora clone makes it seem like the record companies' interests were put ahead of the users' by Apple.

If you are like me, then the answer is bandwidth. Alot of plans only have 500Megs per month of data. I'm looking at plans in Canada

If each song takes 5 Megs then I can stream 100 songs a month if I don't use any additional bandwidth.

Additionally I can't listen to this music during my subway commute into work, which is my primary music listening time.

Rdio lets you sync songs / albums locally onto your mobile device and then doesn't require a connection to play them. Not sure if other services have similar features.

This is a great example of the innovator's dilemma.