If Pinterest isn’t on your radar yet, you might want to tune in. The bookmarking site was just named the third most popular social network in the U.S. — directly behind social giants Facebook and Twitter.

According to a study by Experian, Pinterest’s traffic surged 50 percent between January and February, allowing the network to out-grow services like Tumblr, LinkedIn, and Google+.

Pinterest has seen tremendous growth since it launched in March 2010. Experian also pointed out that site received nearly 21.5 million visits during the week ending January 28, 2012, which was 30 times the amount it receive six months earlier.

According to comScore, Pinterest had 17.8 million unique visitors in February from the U.S. alone. Not only are people visiting, but they’re engaging as well. Pinners spend an average of 89 minutes per month on the site. While that’s nowhere near Facebook’s level of engagement — average users clock 405 minutes per month on the social network — it’s an impressive figure nonetheless.

With all this growth, Pinterest has been sending out a lot of referral traffic — even surpassing Twitter in some cases. Of course, popularity is fickle, but Pinterest doesn’t seem to be slowing down any time soon. It’s definitely time to create an account and start brainstorming ways to integrate Pinterest into your social media strategy.

[Via: Mashable, Image credit: EvelynGiggles]