I'm as big of a bull on Baidu (NASDAQ:BIDU) as you'll ever see, but even I was surprised by the 8% surge in shares of China's leading search engine on Friday.

Despite the likelihood of posting better-than-expected second-quarter results -- as Baidu has done more often than not since going public four years ago -- a few factors still tempted me to sell on the news:

  • Baidu grew nicely during the first three months of the year, and China's economy has improved since then. In other words, the market was already braced for greatness.
  • Expectations have grown lately. Over the past three months, analysts have gone from expecting Baidu to earn $5.51 a share this year and $7.48 a share next year to predicting $5.85 in 2009 and $8.38 come 2010.
  • Baidu's stock has more than tripled since it bottomed out in December, leaving it ripe for a breather.

In short, the bar was high. Baidu simply jumped higher.

Revenue soared by 37% year over year, to $160.7 million. Even more impressively, earnings climbed by 45% to $1.61 a share -- and that was after a $0.17-per-share hit from losses related to the company's recent push into Japan. Analysts were banking on a profit of just $1.43 a share on $158 million in revenue.

This certainly isn't the kind of growth investors have seen in search closer to home. Global leader Google (NASDAQ:GOOG) grew its top line by only 4% during the same three months. If you think that's anemic, Yahoo! (NASDAQ:YHOO) and Microsoft (NASDAQ:MSFT) actually posted year-over-year declines in online advertising.

Even in China, Baidu is growing quicker than the pack. Display-advertising specialists SINA (NASDAQ:SINA) and Sohu.com (NASDAQ:SOHU) aren't riding the same kind of success that Baidu is tapping in paid search.

China's still rolling, and Baidu's market-topping quarter will find analysts revising their guesstimates higher. Given Friday's gains, Baidu is now closer to quadrupling than it is to tripling since its December low.

And that means Baidu is no shoo-in to wow the market in three months. The bar keeps rising, so Baidu had better keep working on its leaping ability.  

Other Baidu headlines to check out: