The problem, I think, is that artists compare Spotify with CD sales, instead of Spotify with piracy. It's hard to determine how much Spotify has decreased both CD sales and piracy, but I'd be putting my bets on it reducing piracy a lot more. It's just so much more convenient.
I don't think they'll ever be able to stretch past $10-$15 a month with a streaming music service. Companies like Spotify/Hulu/Netflix might be better off combining their package to charge a solid premium price (Complete fantasy, I'm aware). It would be like the new cable tv subscription for this generation.
Yeah. My other comment (http://news.ycombinator.com/item?id=4573711) gives some thoughts on this. For me personally, a good music service (the Spotify catalogue is good, but has nothing on iTunes, for instance) would be worth $50 a month alone, whereas I wouldn't pay anything like $90 a month for streaming TV/movies unless it included live sport. But, I think I may be an edge case.
The problem at the moment for music and artists, is finding a feasible business model in a world where streaming music is worth nothing (I'd argue that the Spotify subscription fee pays for convenience, rather than the music itself for most customers).
