I came across an article the other day on Harvard Business in which they discussed the results of their recent Twitter research.
For the project they took a samle of over 300,000 accounts. They found a lot of interesting stats about including :
- Although men and women follow a similar number of Twitter users, men have 15% more followers than women
- We found that an average man is almost twice more likely to follow another man than a woman
- The top 10% of prolific Twitter users accounted for over 90% of tweets
- Among Twitter users, the median number of lifetime tweets per user is one (Apparently yhis translates into over half of Twitter users tweeting less than once every 74 days)
I recommend reading the article in full from the link below 
Link : New Twitter Research: Men Follow Men and Nobody Tweets
I believe the 10%/90% statistic– my experience is that a very small, dedicated group of Twitter fanatics (I count myself among this group, although I am by no means among the most active) is doing most of the tweeting. Everyone else seems to be lurking, passively observing what other people are saying.
-Bill Auclair