Nielsen: Twitter grows user base almost 1,500 percent in May - Business Center - PC World

Twitter grew faster than any other Web site in May, when its unique visitors rose almost 1,500 percent year-on-year to 18.2 million, according to Nielsen Online.

People also spent significantly more time on Twitter, from an average of six minutes and 19 seconds in May 2008 to 17 minutes and 21 seconds last month...