The biggest finding in the new study, An In-Depth Look at the 5% of Most Active Users, is that they found 32% of the top "users" were actually bots. They extrapolated this data and found that 24% of all accounts on Twitter were bots. Now Twitter bots are not all spam there are some useful Twitter bots (here is a short list of top Twitter bots).
Some other interest stats:
- Over 60% of top active users reside in the United States. Followed by UK (6.9%), Japan (4.7%), and Canada (4.3%)
- 33.7% of top active users joined Twitter this year
- 16.5% of top active users Tweet more than 10 times per day
- Retweets accounted for 5.06% of top user's activity versus 4.02% for overall users