HACKENSACK, N.J. — Venture capital investor Charlie Federman took his daughters to a Paramus, N.J., mall one day and came home with an idea for an Internet business with the potential to deliver a coveted demographic — teenage girls who like to shop.

Federman, a managing partner of Crossbar Capital, is the founder of PlumWillow, a website that piggybacks on Facebook to create a social shopping network for girls.

Federman and Crossbar Capital provided the seed money for PlumWillow, and he put together a team of executives experienced in launching Internet and technology companies. He also formed a brain trust that guided the creation of the site — a group of high school interns from Bergen County, N.J., and New York City. One of his daughters created the PlumWillow name, after being given the assignment to think of a name that would be appealing to girls, and that wasn’t already being used by another online business.

“I have hundreds of girls volunteering to help me on a subject matter that they are truly more expert than most of the people in the company because they are that demographic,” Federman said.

Carla Larin, 18, a senior at Bergen Academy in Hackensack, was among the first group of interns. She advised Federman to drop his original idea of a site where girls could dress digital avatars in favor of something closer to the kind of shopping experience girls like. Girls, Larin said, want to be able to talk to their friends and socialize while shopping, a reason many online shopping sites don’t grab teen girls.

“If I’m going to be buying something, I’d rather try it on at the mall and go with all my friends, but with PlumWillow, all your friends are on PlumWillow,” she said.

Federman’s initial inspiration for the site came when he was driving his daughters to a mall and asked them why they never shopped online. “Because it sucks,” they replied. After they returned home, he asked them to look at online retail sites with him and asked “Define ‘sucks’ for me.”

“It occurred to me that the sites we have now have been built in a time when shopping was a solitary experience, before social networks,” he said. For girls, shopping is a social experience, like slumber parties.”

The business plan for the site, which debuted in October, is to focus on building an online community first, and make money later. Retailers don’t pay to be linked with the site, but PlumWillow earns the standard online commission of 3 percent to 7 percent if a PlumWillow user then clicks through to buy an item. PlumWillow executives said the site is already earning some revenue from such commissions.

Federman, who has participated in a number of successful Internet and technology launches, would not specify how much “seed money” Crossbar Capital and other investors have put into the project. “It’s cheaper to start an Internet company than it’s ever been, but it’s never really cheap,” he said.

PlumWillow takes advantage of a decision by Facebook this year to open its social network to other websites that want to build a community of users with a common interest. PlumWillow members log into the site through their Facebook account, and can send shopping-related messages to friends in their Facebook network. The PlumWillow site lets girls create outfits on a virtual palette, picking, for example, jeans and boots that go with a certain blouse or jacket. They then can share their choices with their network.

The members also build virtual closets of their favorite clothes. The items they choose come from the online stores of the 20 retailers linked to the PlumWillow site.

“Here’s the vision,” Federman said: “We know the girl, we know the type of jeans she likes because she’s built closets with us. We also know the jeans her friends have bought. We also know the jeans the community has matched with that shirt. At the moment she clicks on jeans, on a real-time basis, we’ll be able to offer her suggestions,” he said. “Companies will pay us to reach the girl just when she exposes her intent that she’s looking for jeans.”

PlumWillow has almost 5,000 members, and user visits total about 1,000 per day, executives said. Federman and Baron acknowledge that those numbers are small in the vast world of the Internet, but “it’s a nice beginning,” Baron said.