Wired on Friday: Three girls like my hat. I'd be more flattered, but that's three girls out of roughly 150,000. I've been fooling around (but only in the hypothetical, desktop-bound fashion) with Friendster.

Friendster is a website with a pitch I've seen before: it's a networking tool. You give it a list of your friends' names and email addresses. It mails your friends and, if they want, they feed it their friends' names and email addresses. And so on, until Friendster knows more about your friends' friends than you do.

Then it proceeds to tell you all about this network. You can search for common interests in this web of vague acquaintances - or you can dig out new people in your area, or folk who might be good business contacts. It's networking, in the strictly non-technical sense of "working a room" - only in this case, it's a room of everyone you could possibly be introduced to by your colleagues.

I've seen Friendster's like before - a company called SixDegrees tried to pull off the same trick. My concerns then were the same as now.

Firstly, I don't feel entirely comfortable handing over my friends' email addresses to a mysterious company who, for all I know, could be selling them under the desk to a spammer.

Secondly, people "working a room" creep me out enough in real life. Having them crawling all over my preferences in cyberspace and striking up a cold-call conversation with me on the ultra-tenuous basis that they're a friend of Angela's who is a friend of Azeem's is hardly an improvement.

In SixDegrees' case, I don't think I was the only one with these doubts. In the end, that site appeared to be filled exclusively with creepy chancers and not much else, rendering it useless for networkers or casual users. It never seemed to catch fire and shut down in 2000.

Friendster has fared rather better. Since its quiet, no-publicity beta launch in December 2002, the site has mushroomed - it now knows of more than two million people. And, apparently, I know at least 289,000 of them.

True to the old rule (where SixDegrees got its name), most of the world can be reached through chains of just six people. Friendster only tells you about four steps away, but that's enough to give anyone with just a few pals a ridiculous number of vague friends of friends.

Now for most uses, 289,000 names is almost as bad as having too few. There's really not much I have in common, for instance, with Benko, a heavily tattooed realtor from Washington DC who dislikes reading but likes Nu-Electro and nice jeans.

But, then again, Friendster isn't your old networking site. The secret of Friendster's success is that it's a dating site.

Its creator, Jonathan Abrams (who apparently I know via Dan, out of Adam), says, repeatedly, that Friendster is "not just for dating or singles". But sometimes our creations have their own ideas and if Friendster had other nobler intentions they're gone now. Killed mainly, I think, by Friendster's option to include a photograph in your profile - although the whole frisson of a romantic encounter is certainly assisted by including an "open marriage" option in the marital status form, and repeated encouragement from the Friendster system to invite your single friends onboard.

Seen like this, having 289,000 names (most supplying photo) to flick through is a positive boon. Especially when you have at least a chance of striking up a brief conversation: "Don't I know you?", you can ask - or at least, "Don't I know someone who knows someone who knows you from somewhere?"

It's hard to describe quite how addictive Friendster has become to many (although certainly not me, no, no). Even the non-daters enjoy the flirtatious atmosphere, and who doesn't enjoy flicking through endless pictures of strangers and their curious tastes?

As someone who is not looking at anyone or anything beyond my six-month-old daughter's next nappy-change, it has the vicarious amusement of accompanying your friends to a singles' bar.

And I admit that when, in the interests of journalistic investigation, I switched my online setting from "Just here to help!" to "Seeking friends, activity partners (women)", I was flattered to get four messages complimenting me on my photograph.

Well, unfortunately, not me in the photograph. As I say, they liked the hat, which was, for reasons too complex to explain here, a fine Victorian topper.

But enough of the small talk. What, exactly, is the business model for a site like Friendster? As so often online, that is nebulous at best. The site is undeniably popular - it has already leapt into the top 200 websites, roaring past the Wall Street Journal and Barnes & Noble.

But maintaining the site, and keeping track of all those connections, requires a lot of server power and bandwidth, neither of which come cheap. Advertising may cover some costs but there are repeated rumours on the Friendster network of a subscription charge.

Could the world's biggest singles market manage with a cover price? Isn't buying a year's subscription to a dating site a little, well, defeatist?

Friendster faces other challenges too. It has its own vague acquaintances, all with curiously similar interests. Sites like tribes.net and ryze.com have taken the Six Degrees idea and tweaked it to their own ends. Tribes is aimed more at providing useful local contacts, and Ryze ploughs the business-contact furrow of SixDegrees.

If Friendster chooses to go down the subscription route, these sites and more will be eager to catch the quitters. And it's not as if Friendster can survive with a fraction of its sign-ups. The whole point of a networking site is that it only works if as many people as possible are connected.

So, will Friendster blow up as SixDegrees did? I think not. If there's one thing I've learnt on the Net, it's that sites that cater for business need to survive on business terms. But sites that catch the imagination of the general public can sometimes float along - don't ask me how - on the amassed goodwill of their users.

Friendster has a tough and long road ahead of it, with no obvious routes to profitability. But with two million friends along for the ride, something should pop up.