Ad-supported music streaming is now officially legit. Music social network imeem has inked a deal with the fourth and final major label, Universal Music Group, to make its entire digital catalog available for free to imeem members. Music from EMI, Warner Music, and Sony-BMG is already available on the site. Now members can start streaming songs from Kanye West, 50 Cent, Black Eyed Peas, The Killers, Snow Patrol, Maroon 5 and Nelly.

This makes imeem the first social network to have a complete library of full-length music streams from all four labels. (All together, including music from independent labels, imeem members can now listen to 5 million songs—nearly as many as the 6 million available on iTunes, but for free). Cut the labels in on your advertising revenues, and they will play ball. At least, until something better comes along.