Pinterest may be nipping at the heels of its big brother social networks, Twitter and Facebook, with help from America's heartland.

The up-and-coming photo-sharing site has become the third-most-popular social network in the U.S., according to new data from Experian's Digital Marketer report. Pinterest's traffic rose by 50% between January and February of this year, the report said. Its 21.5 million visitors in the last week of January was an audience 30 times the size of what it was six months earlier.

A few insights into Pinterest's user base: Nearly 60% of users were female, and 55% were between the ages of 25 and 44.  That crowd was primarily interested in home decor, crafts, fashion and food -- all of which are, not surprisingly, heavily visual topics.

But perhaps the most interesting tidbit has to do with who's pinning. As with Facebook and other social networks, the highest share of visitors to Pinterest come from California and Texas, the two most populous states. But, the report said, though other social networks and forums get a disproportionate number of their users from the urban Northeastern states (e.g. New York, Massachusetts), Pinterest interest is extra-heavy in the more rural Midwest, Northwest and Southeast.

The audience for Pinterest in states such as Missouri, Utah, Alabama, Oklahoma, Kansas and Iowa was twice or three times those states' audience for other social networks and forums, Experian said. That seems to correlate with high interest in hobbies and crafts -- a mainstay of Pinterest -- from the online audience in those regions.

"The data indicates that Pinterest visitors have a different profile versus their counterparts visiting other social networking sites such as Facebook and YouTube," the report concluded.

That said, water balloon lumieres certainly seem to have universal appeal.

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