I just read a great post on Mashable that breaks down the characteristics of Twitterers (see the pretty graphs here). The analysis is based on several sets of data and makes intuitive sense.

Out of 100 Twitterers:
- 5 are “loud mouths” and create 75% of the tweets. 32% of the tweets in this group are from bots.
- 5 have 100 followers or more
- 50 are lazy and haven’t Tweeted in the last week
- 20 are dead which means an empty account
- 55 are female

So, what can we learn from this? Like most communication channels, there is a small group that does it a lot while a high percent have tried it and don’t actively participate. Blogs have a similar pattern - lots have been set-up, but only a small percent are active. Getting to the people who are active, have a large following and are influencers is critical.