Think back six months. You probably never had heard of a little website called Pinterest.

Now it’s the third most-visited social-networking site in the United States, according to a report released Thursday by Experian Marketing Services, a digital marketing firm.

Pinterest, which lets its users “pin” photos and info from the Internet onto virtual boards, ranks behind only Facebook and Twitter in terms of total visitors, according to the analysis, titled “The 2012 Digital Marketer: Benchmark and Trend Report.”

The ranking is based on the total number of U.S. visitors during March and does not include mobile traffic, according to Experian spokeswoman Jennifer Marshall.

Last month, Facebook had more than 7 billion total visitors; Twitter had 182 million; and Pinterest had 104 million total visits from people in the United States, according to data sent to CNN by Experian.

That ranking puts the newbie site ahead of heavyweights such as LinkedIn, Google+, MySpace and Tumblr.

One caveat: Since the data doesn’t include mobile traffic, sites such as Twitter, which sees much of its traffic from smartphones and tablets, may take a hit in this ranking, said Matt Tatham, another spokesman from Experian.

Pinterest’s traffic jumped 50% between January and February. The report calls the site “the hottest social media start-up since Facebook and YouTube.”

Plus, it can’t hurt when the U.S. president joins your website.

Some other Pinterest-y stats for you to chew on: The site skews female — about 60% of users are women — and to the middle of the country, according to the report from Experian. Pinterest is most popular relative to other social networks in Missouri, Utah, Alabama, Oklahoma and Kansas, the report said.