(MoneyWatch) Although we routinely use social networks to communicate with strangers from around the world, research shows that many Americans don't know a single neighbor by name.
The folks behind Nextdoor hope to change that by popularizing a social network geared to local neighborhoods. "LinkedIn is for your career, Facebook is for your friends and Twitter is for your interests," said Nirav Tolia, the co-founder and CEO of Nextdoor. "Those are the three big ones. Yet where we live, where we buy a home, where we end up spending most of our time and most of our money is not represented."
Nextdoor serves as a place where neighbors can, say, recommend local handymen, rave about the corner coffee shop, find lost pets, report local crime, meet up or just chat about neighborhood issues. Members have to verify where they live in order to join, and they can only join a network designated for their specific neighborhood.
"When you're building a service of people talking about their children, their real names and addresses, and what happens to them in the physical world, it became apparent pretty quickly that privacy was key," Tolia said.
On Nextdoor, using home addresses, contact information and pictures are all optional. None of the information is indexed by search engines, according to the company, and there are no ads that track you around the Internet.
While the site has been around for about two years, it has only recently started to show significant growth. More than 22,500 neighborhoods are on board, compared to 176 in the company's first year. The company has seen more than 50 percent growth in users in the last three months alone, according to Tolia.
Mindi Ries was one of the early adopters. Ries lives in Clifton, a neighborhood in Cincinnati, with her husband and 2-year-old daughter. When she and her husband realized they would be in the neighborhood for a while, they decided it was time to get serious about getting to know their neighbors.
"With both of us working full-time, it was difficult to really get to know them," she said.
Ries and other neighbors started passing out flyers and otherwise spreading information about Clifton's presence on Nextdoor. They went from 10 neighbors signed up to more than 1,000. Book clubs, a monthly "conversations at the salon" club and a cycling club sprung up through the site.
Nextdoor is meant to connect neighbors so they can rely on each other. While users may not want to go online to request a cup of a sugar, they may post that they need crutches to help with a recent injury or a babysitter for Friday night. Another way Ries and her neighbors use the site is to discuss any crime in the area.
"It gives people a head's up," Ries said. "There was a rise in crime in the summer. People were using the recycling carts and trash bins to climb up to get into upstairs windows. When people found out, they decided to lock all their windows. One pocket of the neighborhood caught those kids as well."
To serve this need, Nextdoor this year integrated city services into the site. So far, local governments, including police and fire departments, in 120 U.S. cities are signed on to send out public updates via the site, ranging from snow plow schedules to police alerts.
Despite its growth, Nextdoor still has a ways to go to convince larger swaths of neighbors to sign on. Hattie McDonnell, who lives in the apartment-heavy East Avondale neighborhood of Chicago, is looking for ways to connect to her immediate neighbors, but says it's difficult to get them on board through email invites.
In Chicago, meanwhile, until recently Nextdoor faced competition from the now-defunct EveryBlock, a neighborhood networking and block-level news site that was shut down by its owner, NBC News, in February.
Since then, Chicagoans have been looking for a replacement, and thought Nextdoor is close, they haven't managed to attract quite the same crowd -- only 65 percent of Chicago's neighborhoods are represented, compared to 97 percent in San Francisco, where the company is headquartered.
"I am interested to see how it all rolls out [and] how they ultimately monetize the model given EveryBlock's flop," McDonnell said.
Still, funding isn't an immediate problem for Nextdoor, which has about $90 million in the bank and is backed by such A-list venture capital firms Benchmark, Greylock and Kleiner Perkins Caufield & Byers. But the company will have to refine its business model.
"Eventually we'll have to figure out a way to generate revenue," Tolia said. "We don't anticipate that will take the form of banner ads, and it will never take the shape of charging people."
The company is considering charging for classifieds, which are currently free on Nextdoor, or charging local businesses to list themselves on the site or to advertise. For now, however, it is content to postpone the pursuit of profits in favor of driving growth. In 2014, the company hopes to bring its vision of the networked neighborhood overseas.