60% will leave Twitter, 25% leave Facebook!
http://www.itproportal.com/portal/news/article/2009/4/30/reports-suggests-60-percent-twitter-users-leave-after-30-days/
http://www.allfacebook.com/2009/04/top-application-decline/
http://www.bradleyscout.com/index.php?option=com_content&view=article&id=326:top-10-reasons-to-leave-facebook&catid=8:opinion&Itemid=7
http://canayjun.blogspot.com/2009/03/50-reasons-to-leave-facebook.html
http://www.allfacebook.com/2009/04/top-application-decline/
http://www.bradleyscout.com/index.php?option=com_content&view=article&id=326:top-10-reasons-to-leave-facebook&catid=8:opinion&Itemid=7
http://canayjun.blogspot.com/2009/03/50-reasons-to-leave-facebook.html