(FORTUNE Small Business) – Scott Heiferman, the 31-year-old co-founder of meetup.com, doesn't act like the kind of brash, young dot-com CEO you're used to seeing. Soft-spoken and socially awkward, Heiferman fiddles with his glasses and stumbles over his words. It isn't until he focuses his gaze at the wall-sized world map in his otherwise spare New York City office that he gets to the point. "We're changing the world," he says.

Okay, maybe that doesn't sound so unusual. But it is, for one simple reason: He's probably right. A year ago Meetup.com, a website that allows people to set up face-to-face meetings to discuss everything from Harry Potter to yoga, didn't exist. Today political analysts and campaign managers say that it's helping to revolutionize American elections, and allowing candidates to use the Internet to increase constituent support and publicize their agendas. So far Meetup.com has drawn attention from presidential hopefuls including former Vermont governor Howard Dean; Massachusetts Senator John Kerry and California Senator Barbara Boxer; fans of President Bush; and gatherings of Young Republicans. If--as many experts predict--this is the year that the Internet becomes a legitimate campaign tool, Meetup.com will deserve some of the credit. "Meetup is a big part of what's changing the face of politics today," says Carol Darr, director of the Institute for Politics, Democracy and the Internet at George Washington University.

Oddly enough, Meetup.com's original customers were supposed to be "Elvis fans and knitters," says its VP of communications, Myles Weissleder. That makes sense, given how Meetup.com works: Users log on and find a topic that interests them. If four or more people within the same metro area have signed up for the same topic, Meetup.com will suggest a time and venue. "The goal is to reconnect people with their communities--there's no sense of local these days," says Heiferman, who was inspired, along with co-founders Matt Meeker and Peter Kamali, by the ideas in Robert Putnam's controversial 2001 bestseller, Bowling Alone: The Collapse and Revival of American Community, which bemoaned the isolation of American citizens. Two months after Meetup.com launched in June 2002, Trekkies and Linux programmers were kibitzing at coffeehouses and bars in more than 500 cities around the world.

This past January, Joe Trippi, who serves as campaign manager for Democratic insurgent Howard Dean, got wind of a small group of self-organizing Dean supporters on Meetup.com. He immediately contacted Heiferman to see if he could capitalize on the connection. In response, Meetup.com rolled out a small batch of web services that helped Dean staffers form a better relationship with their Meetup.com constituents, letting them ask for e-mail addresses, send customized e-mail, and link directly to Meetup.com from the Dean campaign's website. By March, almost 10,000 new Dean supporters had signed on, and Heiferman had nabbed two more clients: Senator Kerry, and DraftWesleyClark.com, a site for devotees of the four-star general and potential presidential candidate. Soon Meetup.com expanded its options: For those willing to pay $2,500 to $10,000 a month, the site will make it possible to do things like suggest agenda topics and receive reports that tell candidates when and where their constituents signed. "It's like a dating site for activists," says John Hlinko, the creator of DraftWesleyClark.com. "Suddenly we have a tool to channel all this enthusiasm into something concrete--like thousands of signatures--very quickly." Heiferman is quick to say that even though the campaign managers now have the ability to be more hands-on, the company isn't surrendering its autonomy. "Nobody owns the Meetups," says Heiferman. "Not us, not the Kerry staff, no one. It's merely an automated service, a platform."

When Meetup.com employees first reported to work last year, they couldn't help but notice a huge, laser-printed banner that Heiferman had hung over their desks. The banner's message--revenue minus expenses equals profits--may seem obvious to any high-school economics student, but given Heiferman's history, he may need the reminder. After successfully selling his first startup--Internet advertising agency i-Traffic--to Agency.com in 1999, he created hardware company RocketBoard in 2000. That venture, which blasted through about $500,000 a month, went belly-up in just under a year. "RocketBoard was one of the many companies that lost track of this very basic idea," says Heiferman, pointing to the banner. "As a result, Meetup.com is taking a very non-dot-com approach to becoming profitable." Translation: The company is keeping monthly expenditures fixed ($100,000) while steadily increasing revenues--charging some 20,000 venues $29 to $200 a month to be listed on the site. With receipts doubling every month, Heiferman expects Meetup.com--which nabbed $1 million in venture capital funding last year--to turn a profit by year's end. (The company won't divulge how much cash it currently has on hand.)

But by the end of next year, the elections will be done. Dean's 90,000-plus Meetup.com members might go back to their blogs and Internet dating sites. Can the company outlast the elections? "The election is a spike in usage surrounding a particular topic," says consultant Jerry Michalski, a former dot-com tech analyst. "Meetup has a very simple concept that scales across the whole globe." Of course, that simple concept isn't immune to potential competitors. So Heiferman is trying to solidify Meetup.com's first-mover advantage by securing bigger-paying clients--so far, he's signed up Investors' Business Daily and Fox News talker Bill O'Reilly. "Eighty percent of Meetups have nothing to do with politics," says Heiferman, who wants his company to encourage people to reconnect while turning a profit. "We're not just a business, we're part of a serious cultural trend," he claims.

Heiferman may have given up the dot-com debt spending. But don't ask him to shake off the utopianism just yet.