this DOI), it is clear that Facebook appeals to a particular demographic:
The results showed that Facebook users tend to be more extraverted and narcissistic, but less conscientious and socially lonely, than nonusers. Furthermore, frequency of Facebook use and preferences for specific features were also shown to vary as a result of certain characteristics, such as neuroticism, loneliness, shyness and narcissism.
Similarly, and more importantly for education, in Khe Foon Hew. 2011. Students’ and teachers’ use of Facebook. (Computers in Human Behavior, Volume 27, Issue 2, March 2011, Pages 662–676, see this DOI), we find a pretty damning indictment of the promotion of social media for education:
The conclusions overall suggest that Facebook thus far has very little educational use, that students use Facebook mainly to keep in touch with known individuals, and that students tend to disclose more personal information about themselves on Facebook; hence attracting potential privacy risks upon themselves.