Daisy (Beats by Dre's "Spotify") is trying to do this by partnering with Topspin and we shall see what happens - I'm excited to check it out.
The fact is, all-you-can-eat streaming platforms will never scale to the amount where payouts for plays are significant if they continue with the freemium model. Artists need the ability to sell other products and experiences to those listeners. I'm, admittedly, biased towards the idea that artists need to seek new direct-to-fan revenue streams.
Here's a piece I wrote on Hypebot about this: http://www.hypebot.com/hypebot/2013/01/music-subscription-se...