Summary report giving useful data for Like subscribers, Fans, and Followers from eMarketer- http://www.emarketer.com/Article.aspx?R=1008630
Data pulled from 2011 study from ExactTarget (requires email, etc share)- http://www.exacttarget.com/
Summary report giving useful data for Like subscribers, Fans, and Followers from eMarketer- http://www.emarketer.com/Article.aspx?R=1008630
Data pulled from 2011 study from ExactTarget (requires email, etc share)- http://www.exacttarget.com/