Did March belong to Yahoo! (Nasdaq: YHOO) or Google (Nasdaq: GOOG)? I guess it depends on which market research firm you fancy.

Over in the Google cheering section, comScore shows Google once again gaining search-query market share over Yahoo!, despite uninspiring overall growth. Standing in Yahoo!'s corner, SearchIgnite shows that Yahoo! is eating into Google's share of search advertising budgets.

It's clearly not a knockout by either fighter, but is it a split decision? Both research firms can have it right. Google may very well be growing more quickly than Yahoo!, but advances in Yahoo!'s paid-search platform may also be yielding bigger year-over-year gains in what marketers are willing to pay.

The victor will be declared over the next few days, as Google reports its quarterly results tomorrow, and Yahoo! follows suit next week.

Now is a critical time for both companies, with analysts lowering their estimates on Google in recent weeks and Yahoo! trying to doll itself up for one last shot at getting a sweetened buyout bid from Microsoft (Nasdaq: MSFT).

The comScore data for March shows Google's market share growing to 59.8% of the overall search market. However, it also records year-over-year ad clicks on Google's site coming in just 2.7% higher than last March. This caps off a disappointing quarter for the company, with comScore noting flat year-over-year click gains in January and a mere 3% rise in February.

It's an incomplete picture, of course. Google is no doubt growing more quickly overseas, even in markets like China, where it distantly trails leader Baidu.com (Nasdaq: BIDU). The comScore numbers also don't factor in the leads generated through the company's network of third-party AdSense sites. More importantly, these statistics don't tell us whether advertisers are paying more or less for those clicks, even though the Yahoo!-favoring SearchInsight data may cast a cloud over gains there.

It's only natural to have plenty of questions at this point. Thankfully, with both companies now just trading days away from telltale revelations, answers are on their way.