Those are very good questions and they would make for a great research project. I recently did a survey of several of the top social network alternatives here: https://blogs.law.harvard.edu/internetmonitor/2013/06/14/social-network-alte... The biggest barrier to studying activity on these alternatives was that their emphasis on security and privacy make it very difficult to determine how many people use them, what they use them for, or what groups they attract. However, some networks like Diaspora provide nearly real-time information on how many users they have. Facebook and Twitter still have the most users by far, but several of the alternative networks I looked at also had followers/members on mainstream social networks too. There are many more alternatives available than the ones I examined, but most required considerable technical skills so I didn't include them for the blog's general audience. I'm as interested as Dr. Ess in answers to the questions he posed, but I'd like to add another. Before PRISM, I recall a number of studies which found that people generally would not be willing to pay money for a secure social network which does not mine user data. In addition to Dr. Ess' questions, does anyone know if new studies have been done to determine whether people are now willing to pay for social networks which don't collect and share user data? Rex Troumbley, PhD Candidate Department of Political Science and Alternative Futures University of Hawaii at Manoa