In May 2008, Pew research reported just six percent of Internet users were on Twitter and other similar sites.  In the survey of 1,698 adults conducted in September, also noted women send more tweets than men.  Furthermore, 33% of users on Twitter are 29 years old or younger -- only 4% of users are 65 or older.

"The median age of a Twitter user is 31, which has remained stable over the past year," according to the report.  "The median age for MySpace is now 26, down from 27 in May 2008, and the median age for LinkedIn is now 39, down from 40. Facebook, however, is graying a bit: the median age for this social network site is now 33, up from 26 in May 2008."

A problem with unexpected growth has been lingering server issues, with the Twitter "fail whale" routinely seen during peak traffic times.

Twitter and other social networking services have been popular among younger internet users, but has spread to older internet users, research indicates.  Including Twitter, Facebook, MySpace, and all social networking sites, 47% of internet users are a member of at least one of the sites, a drastic increase from 29 percent in May 2008.

The overall popularity of social networking has led advertisers and others to the growing sector, looking to generate revenue during an economic slump.