What's great about Spotify, is that artists get paid per listen, which favours artists which make great, lasting music, and against those who produce one hit wonders. If people continue to listen to your music over a period of time, the artist will continue to get paid, and that's great (and those who produce one hit wonders get paid a lot at the time, and virtually nothing afterwards).
The problem, of course, is that Spotify doesn't pay very much to artists. Spotify says this is because artists have shitty deals with labels (and I'm sure this is true), but independents also complain about the amount passed on. Spotify, however, last I checked, isn't profitable, so they can't afford to pass on more money anyway. I would happily pay more, but I use it near-constantly at work and at home (easily 6+ hours a day on average). I suspect I'm a minority here.
Ensuring artists get paid enough is a problem we haven't solved yet. I tend to think it'll go the way of free-or-near-free streaming (a la Spotify or Youtube), with albums becoming collectibles like Vinyls, and the vast majority of artist revenue coming from live shows. Unfortunately, this is going to mean labels are going to have to negotiate a cut of live shows with artists to cover album production costs (assuming they're not independent, obviously). I don't mind a one-or-two week delay on streaming sites to give people who really want a listen to buy it first. Of course, this helps drive piracy back up, but for artists, their aim shouldn't be minimising piracy, but maximising the profitability of their work.