Pinterest is now the 3rd largest social network in the US in terms of visits

"Pinterest is now the number three most-popular social network in the U.S., behind Facebook and Twitter, according to Experian Hitwise.
A new report from the researcher shows Pinterest got 21.5 million visits during the week ending Jan. 28, a nearly 30-fold increase over a comparable week in July. Not surprisingly, the site skews female with a 60/40 ration of women to men visitors.
Experian rep Matt Tatham says Pinterest beat its next-closest competitor, LinkedIn, in total visits in February. Tatham says the rankings by total visits for March is as follows:
1. Facebook: 7 billion
2. Twitter: 182 million
3. Pinterest: 104 million
4. LinkedIn: 86 million
5. Tagged: 72 million
6. Google+: 61 million
The report, which tracks visits rather than unique visitors, is based on web traffic and doesn’t factor in visits from mobile sites. According to Experian’s reckoning, Foursquare only got 2.9 million visits in March and Instagram got 10.2 million."

Source:  Mashable, 6th April 2012