For the first time, according to the latest data from Compete, Facebook outdrew MySpace in terms of unique visitors. But Facebook isn't the fastest growing network. Twitter's numbers grew 27.6% in December, and 752% for the year. LinkedIn is up 152% for the year. In fact, the only one here that's losing traffic is MySpace. They better figure out a way to grab a new audience, and fast. Their demographic is growing up. See below for the Compete data.