Information Week is out with a new story ranking the top Internet search firms (by number of searches) for the month of February, 2008.

The results may indicate why Microsoft wants a piece of Yahoo so badly, even though Bill Gates & Co. seem unwilling to up their share-per-price bid for Yahoo.

IW, in a headliner entitled "Microsoft's Search Share Continues To Decline" says that for the month of February, 2008, Google had 5.86 billion searches, Yahoo had 2.14 billion, and Microsoft had 953 million. The magazine cited research provided by comScore.

While framing the internet search in 30-day terms, comScore's data shows that Microsoft's share-per-search has been stagnant over the previous three years. Microsoft saw its search share drop by 0.2% for the month overall.

Why, when it comes to online search, Microsoft is pretty much an afterthought? Information Week says that the company has experimented with a potpouri of search models, all to its detriment.

"There have been repeated shake-ups of Microsoft's search strategy in the last few years, with the company first moving from MSN Search to Live Search, and then creating an entirely new organization for search and advertising, run by Microsoft senior VP Satya Nadella," says the magazine. "Last September, the company held an event called Searchification to unveil an entirely re-architected version of its search engine. Live Search 2.0 was supposed to provide more relevant query results and an easier-to-use interface. But these moves have meant little in terms of Microsoft's success in making inroads against Google."

Thus the desperate cat-and-mouse game between Microsoft and Yahoo. Yesterday I reported that Yahoo rolled out a new campaign to convince shareholders that Yahoo didn't need Microsoft to prosper, that the company was just fine on its own. Today, a rumor out of Redmund, Washington says that Microsoft will refuse to bump its share-price offer for Yahoo, which would only increase the stakes.

But the comScore numbers show that Microsoft needs Yahoo more than Wall Street might have thought. Information Week says that Yahoo represents Microsoft's best shot at the 400-lb. gorilla of Internet searches - Google.

Of course, you can't get anyone at Microsoft to say that.

"When it comes to the core algorithmic relevance, we have matured to a point where we can compete with the Googles of the world," Nadella told InformationWeek. "We need to get to the point where the ability to get that word out broadly gives us the shot. Now our challenge is to make sure people are more engaged with us."