Updated music site heat map post now includes 8tracks and We Are Hunted, based on Compete.com. See http://virtualmusic.tv/2011/02/2010-music-website-heat-map/2/ for full heatmap.
However, according to comScore — which tends to be more accurate — 8tracks is actually larger than a number of the other digital music companies that are depicted as larger in this heatmap. Will report more info later in the week.
(Source: 8tracks)