Media-focused social networking site Imeem is barely 18 months old, but the fledgling site just went four for four in partnering with major labels: Universal Music Group is on board with Imeem’s ad-supported music streaming model. Now Imeem users, averaging 19 million per month, can listen to full-length streamed songs and videos from top-selling artists such as Kanye West, Amy Winehouse and Gwen Stefani, among others.