This is definitively a different application with a different approach to digital music, and they have my thumbs for that. They aren't playing in a shaking ground, so they can easily have success, but things for them aren't as good as the feedback they're having lately seems to.
So, what do these guys give of so new? As a matter of fact, their business is quite simple: artists give their music for free there, music is rated, the best rated songs move from free to costing money and getting more or less expensive depending on being more or less rated. To avoid bad ratings or people not caring about rating at all, they pay money for users that especulate well (telling that a band will start selling well and being right gives good money for the artist and for the raters).
So, where's the flaw? Well, people can simply not buy non-free music, so that since the moment a songs start costing money can be the moment that the song stops selling, until is free again. But comparing that to having the song forcefully free (like in those other services), well... I just guess that no artist has nothing to loose with this.
The only problem I see with this service until now it that it is way too buggy, and has a really small selection of music (yet). Considering that the site is still at it's "Alpha" state, I'm not really worried about it, tho.
Congratulations guys, and good luck.