- 72.5% of all users joining during the first five months of 2009.
- 85.3% of all Twitter users post less than one update/day
- 21% of users have never posted a Tweet
- 93.6% of users have less than 100 followers, while 92.4% follow less than 100 people.
- 5% of Twitter users account for 75% of all activity
- New York has the most Twitters users, followed by Los Angeles, Toronto, San Francisco and Boston; while Detroit was the fast-growing city over the first five months of 2009
- More than 50% of all updates are published using tools, mobile and Web-based, other than Twitter.com. TweetDeck is the most popular non-Twitter.com tool with 19.7% market share.
- There are more women on Twitter (53%) than men (47%)
- Of the people who identify themselves as marketers, 15% follow more than 2,000 people. This compares with 0.29% of overall Twitter users who follow more than 2,000 people.

Download the full report at Sysomos

Reed also Rohit Bhargava's take on the report at the Influential Marketing Blog