Twitter Inc. may be having a great week, since both President Barack Obama and Microsoft founder Bill Gates have started Twittering , but a report released this week by HubSpot Inc. says the site's rate of growth in signing up new users started dropping dramatically last fall.
Twitter had grown very rapidly over the past couple of years but HubSpot , a Cambridge, Mass.-based Web analytics company, said in its latest "State of the Twittersphere" report that the growth rate dropped to 3.5% in October compared to 13% just seven months earlier.
The report did note, however, that a recent study of Twitter users found that they are becoming... well, better Twitterers .
The average Twitter user today follows substantially more people, is followed by many more people, and posts more updates than he did in mid-2009, according to HubSpot. For example, last July, the average user had about 60 followers; by January 2010, that number had jumped to 300.
"The change may be a reflection of the slowing growth rate," the report noted. "Because of the slowing growth, today's population of Twitter users has been using the tool longer than the population several months ago ... experienced users make up a larger portion of the population."
But Twitter users who feel badly that they don't have massive numbers of followers like Twitter giants Ashton Kutcher and Oprah Winfrey can take heart in the fact that 82% of their fellow tweeters have fewer than 100 followers.
The analytics firm also noted that Twitter users are night owls; the hour between 10 p.m. and 11 p.m. is the most active period of time on the site.
HubSpot also found that Twitter is becoming an increasingly international phenomenon.
The study pointed out that last July, 15% of the top 20 Twitter locations were outside of North America. By this month, 40% of the top 20 Twitter locations were outside the U.S., with Brazil, Germany, Singapore and Indonesia making their first appearances on the top 20 list this month.
The study was based on analysis of 5 million Twitter profiles and 6 million tweets.
Sharon Gaudin covers the Internet and Web 2.0, emerging technologies, and desktop and laptop chips for Computerworld . Follow Sharon on Twitter at @sgaudin , send e-mail to email@example.com or subscribe to Sharon's RSS feed .