Interesting concept - build a community around new music and invite artists to participate in posting tunes + mixes that they might not anywhere else, offering up to the community for free/under Creative Commons non-commercial license, then work hard on getting revenue through ads/sponsorship and (I guess) licensing/re-syndication deals for popular tunes posted on the site.
Even if that site doesn't make much from ad revenue its plausible that they could release merch and physical music releases in 6 -12 months and sell a lot of units because of their large community etc...