(Reuters) - Facebook's original friends are moving into politics.

Small investments in NationBuilder, a political campaign software startup, by a tight-knit group of Facebook alumni suggest how they might spread their wealth around Silicon Valley in coming months, especially after the world's largest Internet social network goes public.

NationBuilder said Thursday it has raised $6.25 million in an investment round led by Andreessen Horowitz, the venture capital firm founded by high-tech entrepreneurs Marc Andreessen and Ben Horowitz.

While the bulk of the funding came from the firm, other participants included former Facebook President Sean Parker; Facebook co-founder Dustin Moskovitz; and Dave Morin, a former top Facebook marketing executive.

The industry has been keen to see if there will be a repeat of the early 2000s, when the PayPal Mafia, flush with cash after the e-commerce company's initial public offering, went on to invest in and lead a generation of companies from LinkedIn to Yelp and YouTube.

Facebook, with more than 845 million users, is preparing to raise $5 billion in an IPO that could value the company at up to $100 billion.

NationBuilder's ties can be traced back to company president and co-founder Joe Green, who roomed at Harvard with Facebook CEO Mark Zuckerberg. Green and Parker also founded Causes, a social change startup.

NationBuilder has not been shy about its connections. Green called his latest startup the first Silicon Valley A-list-funded company to venture into the political arena.

Not to puff ourselves up ..., but nobody with this kind of pedigree has ever entered this space, Green told Reuters.

At the same time, NationBuilder's funding points more broadly to a gathering wave of political interest in Silicon Valley. The technology industry has emerged as a vital base of financial support for President Obama's re-election effort, a fact illustrated most vividly by photos of Zuckerberg sitting next to Obama at several private fundraiser dinners last year.

At the local level, Parker and Ron Conway, the angel investor who has also invested in NationBuilder, played a major role in San Francisco's mayoral race last fall, contributing hundreds of thousands of dollars to a political action committee supporting Edwin Lee, who ultimately swept aside challengers.

At the time, Parker and Conway enlisted another political startup they backed, Votizen, to help with Lee's campaign. Votizen also recently closed a round of celebrity funding from the likes of billionaire financier Ron Burkle, actor Ashton Kutcher and Lady Gaga's manager.

Until very recently, politics has been left largely untouched by technology, but it is now ripe for disruption, according to Andreessen Horowitz partner Ben Horowitz.

The wheel was developed 5,000 years before the luggage suitcase with wheels. We're at the point with software and social networking now that applying it to other industries where it's never played before is becoming very realistic.

Software, Horowitz added, can eat politics.

Horowitz - the founder of Opsware which was acquired by Hewlett-Packard Co in 2007 - and Andreessen, who co-founded Netscape - which AOL bought in 1998 - became an investment team in 2009. They formed one of Silicon Valley's most closely watched venture capital firms that would hold stakes in some of the hottest Internet companies, including Facebook, Twitter and Zynga.

LET'S ORGANIZE

NationBuilder's software allows campaign organizers to keep track of both potential voters and campaign staffers and volunteers in one comprehensive action management interface. The software comes packaged with publicly available voter rolls, which users can use to contact and interact with voters at increasing levels of engagement.

NationBuilder, for example, will notify the campaign when a voter has registered to receive email updates — signaling that the campaign may consider calling the person as a next step, or if field volunteers on a precinct walk might want to drop by the house. The software also manages social media, the campaign website and traditional communications with campaign staff.

Volunteers may be assigned tasks and rewarded with points based on metrics like phone calls made, or doors knocked.

The ability to organize people to do something is very, very difficult and certainly hard to pull off in software, said Horowitz. But they seem to have done it.

So far, clients include parts of Republican primary candidate Newt Gingrich's organization and the British Labor Party, NationBuilder CEO Jim Gilliam said. And last fall, a 23-year-old man defeated a 19-year mayoral incumbent in the township of South Orange, New Jersey, by a margin of 12 votes after adopting NationBuilder, Gilliam said.

NationBuilder, which has just a half-dozen or so employees, will begin selling its software at $20 per account to campaigns, with additional charges for add-ons, such as mass email and text messaging capabilities.

The idea first leapt out at Green when the then-Harvard undergrad got a taste of political organizing after volunteering on Sen. John Kerry's 2004 presidential campaign. He returned to Cambridge with the first rough ideas of a startup.

I tried to convince to my college roommate to build a political social network, he — now famously — built a college social network instead, Green said dryly.

Today, Green argues that his software has broad applications: it could empower anyone from an aspiring county prosecutor to an author on a book tour looking to build a network of fans.

We're trying to make everyone a leader, he said.

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