Facebook founder Zuckerberg is No. 1 page on Google(PLUS)

Any guesses as to who is the most popular person on Google(PLUS), the company's new social networking service? Ashton Kutcher , perhaps? Or Lady Gaga?

Actually, that title is currently held by Mark Zuckerberg , the founder and chief executive of Facebook - the very service that Google(PLUS) was meant to challenge.

As of Tuesday evening, Zuckerberg had nearly 35,000 people following his updates on the service, more than anyone else in a broad survey of Google(PLUS) profiles by Social Statistics, an outside service. His fan base exceeds that of Larry Page , one of the founders of Google and its recently appointed chief executive, who had only 24,000 people following him.

Google(PLUS) is less than a week old and is still not yet widely available to the public. But access to the service, which lets people share photos, links, status updates and video chats with groups of friends, is already in high demand among early adopters who are eager to play with its features. That includes Zuckerberg, who apparently signed up to keep tabs on his new adversary.

Neither Facebook nor Google confirmed whether Zuckerberg's profile was real. But his account is linked with those of several Facebook executives who are also on Google(PLUS), including Bret Taylor , the chief technology officer, and Sam Lessin , a product manager, suggesting that it is authentic. Zuckerberg has yet to post anything that can be seen by the wider public. His own description on his profile page says simply, "I make things."

"It makes sense that he wants to check it out," said Boris Veldhuijzen van Zanten , who is one of the founders of the technology blog The Next Web and built the Social Statistics service on a whim. "Everyone wants to keep an eye on the competition."

Zuckerberg's visit to his rival's turf may be an indicator that the social networking wars are reaching a new pitch. Plenty of major companies, including Google, Apple and Microsoft , are eager to gain access to the potentially lucrative trove of social data and other information that people share on these services. Facebook has long reaped the benefits of having access to such data, which helps it aim its advertisements more precisely.

"The battle for the future of the Web lies in the social experience," said Ray Valdes , an analyst at Gartner Research .

Facebook also has the world's biggest map of the connections between people. It is not possible to transfer data about one's Facebook connections into Google(PLUS), so most users will have to rebuild that list on the new service. On Tuesday, Facebook blocked an add-on for Google's Chrome browser that was created by an outside programmer and gave people a way to import their Facebook contacts into services like Google(PLUS). Facebook said the add-on violated the company's terms of service.

Google is hoping to bring its new social network to the iPhone and iPad through applications it has submitted to Apple. In the past, Apple has let apps created by Google linger in limbo, without approving or rejecting them.

So far, Google's new social service has generated positive comments from those with early access, in a turnabout from Google's earlier attempts to woo the masses with social services like Wave and Buzz, which were met with lackluster responses and concerns over privacy.

Stephen Shankland , a writer for the technology news service CNet, said that Circles, a feature that lets people sort their friends into groups for more private sharing, was "the biggest improvement, far and away, over Facebook."

Adam Pash , a blogger at Lifehacker, described the service's Hangout feature, which lets people video chat with as many as 10 friends simultaneously, as "the best free video chat we've seen."

Even Tom Anderson, a co-founder of MySpace who was famous for being every MySpace user's first "friend," weighed in on his Google(PLUS) page, saying the service "does seem like it could take a bite out of Twitter ."

But will Google(PLUS) end up being a mainstream hit? Jeremiah Owyang, an industry analyst with the Altimeter Group , said it was not clear that the successes of Google(PLUS) would extend beyond its early test phase, during which the limited invitations are largely being shared among technology industry people, bloggers and journalists.

"The other 600 million members of Facebook are already heavily invested in Facebook and their FarmVille farms," Owyang said.

Facebook says it is not worried about the competition.

"We're in the early days of making the Web more social, and there are opportunities for innovation everywhere," said Jonny Thaw , a spokesman for the company.

Beginning of the end for Facebook?

Barack Obama and Mark Zuckerberg at Facebook HQ in April (Photo: AP)Here’s a sad statistic: Facebook users spend 23 hours of every month browsing the website. That’s 500 million people staring at a computer screen as a social network swallows up 700 billion minutes of their time. Shouldn’t they all get a life?

The bad news for Mark Zuckerberg, Facebook’s 27-year-old billionaire creator, is that many people are doing just that. They’re using Facebook less, or leaving it altogether – which is known, would you believe it, as “Facebook suicide”.

Figures show that 100,000 British users deactivated their accounts during May, reducing the total number to 29.8 million. And six million logged off for good in the United States. What started off as an exclusive online social club at Harvard University has saturated Western society. Now it could be on the way down.

Facebook suicide is still too bold a move for some. It would be unthinkable for a 16-year-old to kick the habit. Your teenage children might tell you they are “revising” for exams upstairs, but how many hours have they frittered away, sharing hilarious YouTube clips with friends or “poking” each other? For this crowd, Facebook has penetrated every facet of their lives. It is how they communicate (they don’t use email or text messages). It is how they swap articles and videos. As one technology writer put it recently, for them “it’s becoming a web of its own”. Just as Zuckerberg planned.

For others, young twentysomething professionals, for example, it’s a lot easier to quit. My friends use Facebook as a kind of address book, a back-up to their iPhones. At university, we would compulsively check the website because everybody else did. But these days, indifference is catching on. It’s a social epidemic in reverse.

There’s one over-riding reason for this: once you’ve entered the world of work, concerns for privacy become more urgent. That midnight skinny dip at the Majorca beach party was a laugh – but there’s no need to share it with your boss. The dangers of thoughtless social networking apply to all, whether you’re a soldier in Afghanistan, or an over-friendly juror in Manchester.

Facebook is understandably coy about revealing sensitive commercial information such as the average age of those leaving the website. It would rather tell us about its huge growth in places like India, the Philippines and Indonesia – tens of millions of Indians and Filipinos are signing up to Facebook every year.

The problem is, like Western 13-year-olds, they don’t have much buying power. They spend less cash online (Facebook games can be as expensive as online gambling) and are worth less to advertisers, who would rather attract yuppies in Britain and America.

As Adrian Hon, a British technology entrepreneur, told me: “On the surface, Facebook’s losses in the US, UK and Canada are more than balanced out by its rapid growth in emerging markets such as Brazil, India and Mexico. The problem is that a user in a rich country such as the US or UK is far more valuable to advertisers – and to investors – than a user elsewhere. If this trend continues, there’ll be a lot of tense meetings at Facebook HQ.”

Zuckerberg is the sort of Silicon Valley CEO who strolls into meetings wearing flip-flops and shorts. For the moment, he’s unlikely to be bothered by this news.

One report yesterday suggested that Facebook will float in early 2012 – and that it’s looking for a valuation of 100 billion dollars. It’s no wonder Bill Gates is teaming up with Zuckerberg for his latest philanthropic venture. But even Gates might struggle to explain Facebook’s supposed value. Or, for that matter, why LinkedIn (an online business network) is said to be worth $8.5 billion. Or why Groupon (a website that sells coupons offering discounts) is valued at $750 million. None of these companies has revenue that corresponds to those figures. Even Facebook’s total estimated income was only $2 billion last year. Have we learnt nothing from the dotcom crash a decade ago?

A cynical investor would say we haven’t. Websites are being valued by the number of people using them, instead of according to how much money each user brings to the table – as if a wealthy Californian were worth the same financially as an Indian student in a Calcutta internet café.

The spate of “Facebook suicides” in the West should put the fear of God into the smooth executives of Silicon Valley. The tech bubble is impressively large at the moment, but what happens when it pops?

There are two possible scenarios. First, Facebook survives but is vastly reduced in size. The alternative is what gives Mark Zuckerberg nightmares: a new social network appears from nowhere and wipes the floor with its rivals. Sound familiar?