SAN FRANCISCO: Twitter is the fastest-growing "member community" site in the US, posting an uplift in user numbers of 1,382% for the year to February 2009, meaning it was well ahead of more established rivals including Facebook on this measure.
According to Nielsen, over 7 million Americans visited Twitter in February 2009, compared with a total of just 475,000 in the year-ago period.
In terms of overall growth, Zimbio, a social media site billing itself as an "interactive magazine", took second place, with its number of unique users in the US rising by 240% from 809,000 to 2.8 million.
Facebook was in third spot overall, with an improvement of 228%, but dominates in terms user numbers, which rose from 20 million in February 2008 to 66 million a year later.
In fourth position was Multiply, the blog, video, photo and music-sharing portal, which recently bought MSN Groups from Microsoft, and has increased its user base from 821,000 to 2.4 million over the course of a year, an uplift of 192%.
Wikia, a community site that allows people to create and edit content on any topic, made up the top five, having boosted its user numbers by 172% for the year to February, from 1.4 million to 3.8 million.
Data sourced from CNET; additional content by WARC staff