When the 2010 general election is scrutinised by academics a few decades from now, one phrase is sure to bob to the surface. 'The Mumsnet election' will either be seen as an important early milestone in the evolution of the great national - and maybe global - institution that Mumsnet has become. Or it could prove to be no more than a footnote relating to an enterprise that flourished briefly at the dawn of the 21st century before it was overtaken by a more cutting-edge social networking phenomenon and drifted to the fringes of cyberspace, only to disappear for ever.
Which of these scenarios will come to pass is hard to call right now. But the fact that an enterprise set up by two mothers at the height of the dot.com boom on little more than a wing and a prayer has survived at all, let alone managed to persuade leading politicians of all hues that it is indispensable, ranks as quite an achievement.
Gordon Brown was the first of the leaders to visit Mumsnet's offices for a webchat last October; he was followed a month later by David Cameron and, in January, by Nick Clegg. Other politicians who have been falling over themselves to hitch their keyboard to the Mumsnet server include Ed Miliband, Harriet Harman, Ed Balls and David 'two brains' Willetts.
For the uninitiated - which means you're probably male, childless or both - Mumsnet is a kind of web portal that describes itself as 'by parents for parents', albeit, in practice, just 1% of users have a Y chromosome. Its main business is talk, with the conversation embracing conception tips, pregnancy, childbirth, breastfeeding, baby foods, nursery and schooling, plus a raft of topics that have less to do with children, including relationships, sex, books, travel and, of course, politics. A particularly popular strand is dubbed 'Am I being unreasonable?' and allows users to rant about just about anything.
The 'Mumsnet election' tag was dreamed up by Rachel Sylvester of The Times, who noted that 'all the parties have decided that women are the key to electoral success, that the family will be a critical issue when the country goes to the polls and that the internet is a vital campaign tool.'
And it's a label that Mumsnet co-founder Justine Roberts is in no hurry to disown. 'We are totemic of something, even if that doesn't mean we hold the key to the election,' she reflects. 'Women are important in this election because they are less tribal and more floating, more swingable than men. And all three leaders have young children, so family issues are naturally at the forefront.'
The question is, can the remarkable degree of influence and the impressive user base of Mumsnet be converted into something that is financially sustainable and even commercially successful? Will it make the leap from community to become a gold-plated brand and money-making machine such as Saga is for the over-fifties? Or would success be seen by its loyal followers as treachery, a betrayal of the community values that attracted them in the first place?
These are just some of the questions I'd been mulling over before meeting Roberts at the cringingly named 'Mumsnet Towers', which turned out to be a floor in an anonymous office building in Kentish Town, north London. Considering the volume of chatter on the site, the place is eerily quiet, with only half a dozen of the 25-odd staff there, thanks to flexible working.
Back in 2000, Roberts had the idea that became Mumsnet during her first holiday with her twins at a resort in Florida. 'All the parents were moaning how un-child friendly it was, and how they wished they'd known,' she says. 'So the idea I had was for parents to provide each other with peer-to-peer information and advice.'
Roberts was not entirely lacking in business acumen: she'd worked as an economist and strategist at Warburg, quitting the City when she concluded it was incompatible with children, to become a sports journalist. Even that didn't work, as it was male-dominated and meant working mainly evenings and weekends, so she was looking for an occupation that would fit in with family life. She roped in TV producer Carrie Longton from her ante-natal class, on the promise that they could work when it suited and hold meetings in the Jacuzzi at the gym.
With the dot.com boom raging, they set out to grab a slice of the riches on offer. 'We were close to raising ú4.5m, but it fell through when boo.com went bust. It's probably a good thing, because we would have been saddled with huge overheads.'
Instead, they set up with a ú25,000 loan from a friend, and adopted a less pressured organic route to growth. Mumsnet quickly evolved in a way that hadn't been entirely predicted: a piece of forum software purchased for ú25 became the Talk section, which now accounts for 85% of traffic; and it was soon clear that mums were the main audience. ('Men don't chat in the same way - we do have a section for them, but they tend to use the site mainly searching for information.')
For five years, neither founder even took a salary, as Mumsnet slowly built up its numbers and developed a modest income stream from advertising. What first put Mumsnet on the map was a row with parenting guru Gina Ford in 2007; she sued when parents posted comments that she considered defamatory, and although the company ended up making an apology and paying undisclosed damages, the publicity sent the number of users soaring.
Now Mumsnet receives 20 million hits a month and 20,000 posts a day, with 200,000 signed-up members and an estimated one million users. (The only incentive to sign-up is that you can post, but Roberts says: 'Our survey indicates we have 20 lurkers to every poster.') These are numbers that should make it of serious interest to advertisers, as they have to politicians. Roberts is quick to point out that Mumsnetters are a highly educated group with 75% having a degree.
Indeed, advertising is the mainstay of Mumsnet's business, accounting for about three-quarters of last year's revenues of approximately ú1.7m. Banner advertisers range from the predictable parent categories of pushchairs, washing detergents and educational publishers to those with more of a lifestyle angle: Boden and Mark Warner are two prominent supporters.
The challenge has been to broaden the advertiser base. 'Advertisers do tend to look at us as mums with babies,' says Jules Kendrick, Mumsnet's commercial manager. 'But our users buy clothes, perfumes, property, everything.'
Surveys and consumer testing of products have provided a more subtle form of advertiser revenue and have landed Mumsnet's biggest fish to date, carmaker Ford. Mumsnet may have put off some advertisers by taking an ethical stance: it declared itself a 'Nestle-free zone' and turned away McDonald's after consulting users. 'We won't do cosmetic surgery advertising and we're very sceptical about slimming,' says Roberts. 'We also won't take formats like expandables and pop-ups. Our policy is not to take any advertising that contradicts our aim to make parents' lives easier.'
Other income comes from click-through to the stores in Mumsnet Mall and from a fledgling move into offline content, most notably a range of Mumsnet guidebooks.
But although the potential for commercial exploitation may look huge, it's an idea that Roberts baulks at. 'It's not that we don't want to make money, but it hasn't been our priority,' she says. 'I'd like to create a different model, where we can ethically make money, with the consent of our community.'
This ambivalence towards raw commerce is reiterated when she describes Mumsnet as 'something that is not quite a business'. The community, as she sees it, is Mumsnet's stakeholders, and there's no room for investors or moneymaking activities that would alienate them.
Plans are, nevertheless, afoot for new moneymaking ventures and Roberts does not rule out introducing pay-walls for some of Mumsnet's content in the manner of Rupert Murdoch's newspaper empire, but is determined not to exclude people who can't pay.
And further evidence that Mumsnet is not a conventional business comes from its campaigning activities. So far, it has taken up the cudgels on a range of issues, from opposing formula milk to helping families in the developing world. An advertising campaign that declared 'Career women make bad mothers' was pulled after a mass letter-writing campaign on Mumsnet; while an 11-point code of practice to get better care for women suffering miscarriage is set to be adopted in large part by the Department of Health.
The picture, then, is of an enterprise that is more than just a business, bringing together a community of parents, wielding significant influence, campaigning on ethical issues and providing fulfilling employment to its people. So far, so good. Yet Mumsnet also has its critics - quite a few of them - and their viewpoint is damning. Libby Purves recently wrote: 'The Mumsnet obsession is a patronising sideshow.' Many women complain that while Mumsnet garners all the attention, it doesn't represent them, while more specific is the complaint that its Talk forum is full of bullying and abuse rather than the sisterly love it is meant to enshrine. As one reader puts it: 'Foul-mouthed and vicious I found it, in my one brief venture. Hunting in packs. Nasty.'
And there's another, potentially more serious charge; that Mumsnet is not in control of its message. Newspapers and other traditional media decide on their own editorial stance, which enables them to set the tone of their conversation and pitch it to their audience. In this way, they can effectively manage and strategically guide their own brand. But it is Mumsnet's users who decide what they want to post about, and nothing is censored before it appears on the site. The Gina Ford case highlighted the ease with which a forum such as Mumsnet can be hijacked by one vociferous group, resulting in potentially costly litigation.
Roberts' response is to argue that Mumsnet is not a publisher but a platform on which it is the community members who provide the content, and which Mumsnet facilitates. Users are all encouraged to be moderators; by reporting unacceptable comments, they can draw attention to them and get them removed - which provides a handy defence mechanism, if nothing else.
And she's unapologetic about the robust nature of argument and debate on the site. 'People say Mumsnet is more aggressive than other parenting sites, and it's true that we don't delete people for being unsupportive to the original poster.' There are, she concedes, those who complain that Mumsnet is no longer what it was and preferred it when it was smaller, but her response is blunt. 'Mumsnet is there to make lives easier and the moment it's not doing that for you, perhaps you should log off.'
It's inevitable, she feels, that as their children grow older, many women will no longer find Mumsnet so relevant, while the pipeline of 'newbies' - usually new mothers - are what provides the community with its lifeblood.
In any case, she proudly defends the real support and connectedness that Mumsnet provides to a group that has too often suffered from feelings of isolation. 'Our busiest time is during the evening, when many women log on and settle down with a glass of wine just to have a good chat,' she says. 'I get 10 e-mails a week saying: "This has saved my life." It has become a labour of love.'
Election aside, Mumsnet is a social phenomenon of our time - one that you can love or hate - and whether or not it finds a way to convert into a truly profitable and sustainable business, it has certainly trodden a path that demonstrates the power of communities in the digital age.
Roberts says her greatest sense of achievement comes not from having tea with Gordon Brown in Downing Street but from 'the overwhelmingly supportive nature of most users and the small acts of kindness that take place between them every day'. It is, she adds, 'replacing a wider community that we've lost.'