IT seems to help Chinese dot-com firms that want to list overseas if they identify themselves with global industry names.

Thus we have a "Facebook of China" list that includes social website Renren.com, which completed its initial public offering in the United States last week, and social website Kaixin001.com, which is expected to issue shares in the US later this month.

Other Chinese sites expanding into social networking - including Sina Corp with its Weibo miniblog service, Tencent Inc's QQ and the country's biggest online search provider, Baidu.com Inc - are also getting tagged under the "Facebook of China" label by media and industry observers.

If I were an overseas investor, I couldn't help but wonder how many "Facebooks" can exist in China? And which, if any, are most like the actual Facebook?

One answer may be as surprising as it is disappointing. In my opinion, there is no "Facebook of China" and there won't be one any time soon.

No Chinese dot-com firms have reached the level of what Facebook offers in the US Internet market, such as high penetration, wide impact and coverage, and a mature business model.

"Everyone wants a piece of the Chinese Facebook, but in a competitive sector, investors should consider the possibility they are buying a piece of the Chinese Friendster," Tom Orlik said in a Wall Street Journal article.

Friendster is one of the earliest biggest social websites, but it has lost its majority market share to Facebook and MySpace.

Last week, Renren shares rose from an IPO price of US$14 a share to US$18.01 - a 29 percent gain on the first trading day. By the end of the week, however, Renren had dropped to US$16.80.

A Reuters blog entitled "China's hot Facebook clone will cool down" signals that some Western investors are beginning to grasp what's going on. There is no "Facebook of China." Let's explore that rationale in terms of the attributes that have made Facebook what it is today.

Dominant market position

No Chinese social website has the dominant position Facebook enjoys in the US.

Facebook has 155 million users there, accounting for 65 percent of the US Internet population. By comparison, Renren, which claims to be the biggest social website in China, has about 31 million users, or 7 percent of the Chinese Internet population, according to tech blog Techrice.

Renren is one of many players in a crowded, competitive online social landscape, up against a batch of rivals that include Tencent's QQ, Kaixin001, Sina Weibo and 51.com.

Sina Weibo, one of China's hottest new online social sites, has attracted about 100 million users, but that's less than a fourth of the domestic Internet market.

Though both Tencent and Baidu have dominant positions in the instant messaging and search sectors, it is still taking both of them a long time to shift current users to their newly developed social platforms Pengyou and Qzone.

The social networking sector is a winner-take-all battleground because users flock to where most of their friends are and advertisers follow.

Wide impact and coverage

Facebook, though it originated from a campus network, covers nearly all demographic, geographic and generational sectors of US society. It's so widely used that the noun has become a generic verb. It's normal to see messages like: "I have Facebooked your mom."

In China, on the other hand, social websites have largely focused on target groups of netizens. Because China has more than 450 million Internet users, exceeding the entire population of the US, such fragmentation was probably inevitable.

Like Facebook, Renren originated from a university network under the name Xiaonei, which translates as "campus insider." Its main user base largely remains university and middle-school students.

That's a relatively small base when you consider that about 15 percent of Chinese students go to college, compared with about 50 percent in the US.

Among other Chinese social websites, Kaixin001's main demographic is the urban white-collar worker, and 51.com attracts school students and rural residents.

Sina's Weibo has its spotlight on media and celebrity users, who seem to lack interaction with more grassroots users. On the other hand, QQ is popular with everyday users but lacks the sparkle of celebrity and high-profile business users.

Mature business model

Based on a global user base of 500 million, Facebook has the bargaining power to derive considerable income from advertising and the social games sector. It's also easy for it to kick off new services and applications, such as online coupons and virtual currency services.

The only remaining question is: Will Facebook go public and what will be its valuation if it does?

Though sites such as Kaixin001 and Renren have tried to copy Facebook features, they are still grappling to construct the right business model for the Chinese market.

Without the same imposing user bases, those Chinese firms are finding it difficult to generate income from social games and to establish their own social kingdoms like Facebook.

Other firms, such as Sina, Tencent and Baidu, have large user bases but have yet to parlay them into a complete kingdom containing social networking, third-party applications, games, location services, search services and even virtual currency systems.

In my opinion, the latter three companies have the wherewithal to turn themselves into reasonable facsimiles of Facebook, but they're not there yet by a long shot.

The closest true Facebook model in China is some combination of Sina's Weibo, Tencent's QQ and Kaixin001, or Renren's interface. But it's all in the dreaming stage right now.

Last but not least, Facebook is now unaccessable in China. No official reason has ever been given.

It's still uncertain whether Chinese regulators who determine the country's Internet landscape will allow Facebook into the country.

Mark Zuckerberg, Facebook founder and chief executive, visited China at the end of last year and met with representatives of the top Internet firms in China, including Baidu, Sina, Alibaba and Tencent.

There have been a lot of rumors that Facebook may team up with Baidu to facilitate the US company's entry into the market. That could certainly shake up the social networking sector.

But for now, we just have imperfect clones of Facebook in China, and that seems set to continue for some time.