Forrester found that the number of people who actively maintain a blog, write articles, or upload videos and music in the U.S. has actually dipped from 2009-2010. 
This due, in part, to the unique traits required to be a "creator" of content. And at this moment, the number of people interested in or participating in these special behaviors has plateaued.
via Social Media Today – The world’s best thinkers on social media http://feedproxy.google.com/~r/socialmediatoday_allposts/~3/yuwfieKoz7I/social-media-hidden-costs-success