Although men and women follow a similar number of Twitter users, men have 15% more followers than women. Men also have more reciprocated relationships, in which two users follow each other.
These results are stunning given what previous research has found in the context of online social networks. On a typical online social network, most of the activity is focused around women — men follow content produced by women they do and do not know, and women follow content produced by women they know.
The study Economix cites includes two other interesting facts:
Among Twitter users, the median number of lifetime tweets per user is one.and
[T]he top 10% of prolific Twitter users accounted for over 90% of tweets. On a typical online social network, the top 10% of users account for 30% of all production.
Both of these two facts stand in marked contrast to the typical image of Twitter as the outlet for the self-obsessed, arguing that most Twitter users are more interested in what other users have to say than in broadcasting themselves.
Of course, there are other possibilities, not the least among which are that many Twitter users create accounts in order to give themselves the impression of proximity to Twitter's many celebrity users, and that high-volume business Twitter users skew the data in a way that they do not on Facebook.
Those wishing to do empirical verification of their own, and who wish to include an example of the self-obsessed Twitterer in their sample can follow me at http://twitter.com/craiggav.