Spotify's CEO lays out his buisness vision

>The main reason people want to pay is portability. ... With social, when people interact, the more music they share, the bigger library they build, and the bigger value Spotify becomes. The music service that is the simplest, fastest, and most social -- that's the one that will win.

Although mobile and social are tossed around so much they have almost become buzzwords, this is the most simple and direct explanation I have read that shows how these technologies integrate into a path for profitability.

I pay for Spotify, as a US customer, and have gotten huge value out of it. I was a Zune subscriber for 2 years (I think); it was a great, valuable service to me. I eventually cut it off because I lost my Zune and didn't want to buy another. Spotify fills that niche, without tying me to a platform AND $5/mo cheaper. Love Spotify, hope they all become gazillionaires.