I recently came across an interesting article in Advertising Age which quoted a joint study by ComScore and Facebook.  The study stated that brand posts actually reach more friends-of-fans, than fans itself which shows how much leverage social media can really have.  To use the example highlighted in the article, a Starbucks post to its fan page in May reached about 6.5 million of its 24 million fans.  An additional 11 million people were reached by fans "liking" or commenting on the post - these were the friends-of-fans.  Ad Age noted that the 17.5 million "reached" by the Starbuck's post didn't go to the Starbucks brand page, but saw the activity in the form of a news feed or friend's profile view.  Still, a tremendous result and that combined reach of fans and friends-of-fans equates to 8% of total U.S. internet users -- at zero-cost!   The link to the article is below:

http://adage.com/article/digital/a-facebook-fan-worth-depends-number-friends/228923/