A new report from Sysomos based on an analysis of more than one billion tweets over a four month time period (December 2009 – March 2010) shows that Twitter use is still growing, particularly outside of the United States.

The number of tweets per day overall has increased by 30% in the past four months to over 53 million tweets in the month of March 2010 (up from 40 million in December 2009).

The chart below shows the Twitter growth within and outside of the United States.  In all three months tracked in the study, U.S. growth was surpassed by non-U.S. growth.

International growth rates for Twitter definitely bode well for the site’s future, but so do the active user retention statistics that show more Twitter users sticking with it than ever.  According to the Sysomos report,

“People who had been on Twitter for less than three months kept a steady presence, accounting for about 22% of total tweets in each of the past four months. This suggests new users are sticking around and establishing a solid presence.  People who had been on Twitter for more than nine months increased their activity in a major way to 41.6% of total tweets in March from 26% in December. This suggests that as people spend more time on Twitter, they tweet more frequently.”

Clearly, Twitter isn’t going anywhere.  In fact, it has become an integral form of communication, publishing, and marketing in 2010 and beyond.

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