Music marketing firm RootMusic has published an infographic drawing on data from the top 250 musicians on Facebook, trying to dig out some key trends in Facebook marketing from 2011. It says the top 250 artists have a total of two billion Likes, with seven out of the top ten most popular pages on the social network belonging to musicians, who have an average of 43 million Likes each. RootMusic adds that 89% of top artists are using music apps on Facebook, with the five most common being YouTube, its own BandPage, Vevo, Bandsintown and FBML. The top 250 artists post 1.6 times a day on average, and 88% post new content to their wall on a weekly basis. It also notes that 35% of top artists have their Facebook Wall as the first thing fans see when visiting their pages, while 31% have their RootMusic BandPage.