(Nasdaq: BIDU) thinks, therefore it IMs.

China's top search engine is throwing its hat into the instant messaging ring, a fast-growing market dominated by Tencent's QQ and Microsoft (Nasdaq: MSFT), with this morning's introduction of Baidu Hi.

The move makes perfect sense. Baidu has used its search engine prowess to launch sticky community sites devoted to everything from discussion boards to social networking. It's the perfect pivot point. If folks are text chatting in real-time online, why wouldn't Baidu want a piece of that?

It's also a booming market. According to Web information company Alexa, is the second most popular website in China, trailing only Baidu. Yes, the hot IM platform is getting more traffic than SINA (Nasdaq: SINA) and Google (Nasdaq: GOOG). It's not as easy to monetize an IM application as it is with search, but it's more about keeping up with the trends and eyeballs than the pocketbooks.

The key to success comes from paddling into new revenue streams without diminishing the brand as a search engine workhorse. Yahoo! (Nasdaq: YHOO) didn't necessarily fall behind Google in search usage because it dove into things like job listings, dating personals, and instant messaging, but the lack of focus probably didn't help.

The good news is that Baidu hasn't slipped despite launching dozens of similar forays in the past. Even more recent moves like launching its search engine in Japan and developing an eBay (Nasdaq: EBAY) clone haven't diluted the brand's popularity. New initiatives also haven't materially weighed down the company's earnings power, going by this month's fourth-quarter report, which found earnings soaring 79% despite the Japanese expansion.

If it isn't obvious to you by now, I'll state it loud and clear: I like both this move and Baidu as an investment at this point.

I recommended shares of Baidu to Rule Breakers newsletter subscribers in the fall of 2006. The stock has tripled since then, but earnings have grown even faster. In other words, Baidu is now trading at just 40 times next year's profit target. Clearly it is growing faster than that. Baidu may be going Hi, but the valuation appears to be anything but high.

Hi, Foolishness:

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Longtime Fool contributor Rick Munarriz has been a fan of China's growth stocks for several years now, even though he does not own shares in any of the companies in this story. He is part of the Rule Breakers newsletter research team, seeking out tomorrow's ultimate growth stocks a day early. The Fool's disclosure policy sends a big "Howdy" to all its friends.