Microsoft's worldwide search share for its year-old Bing search engine may be stuck in the doldrums of summer -- along with the other two major search engines -- but it appears to be up in terms of U.S. searches, according to a new report.

The latest report by Experian Hitwise found that Microsoft's (NASDAQ: MSFT) Bing gained 6.7 percent from May 29 to June 26.

At the end of June, Bing had 9.85 percent of U.S. searches compared with 9.23 percent at the end of May. Meanwhile, Google's (NASDAQ: GOOG) search engine went from 72.17 percent search share at the end of May to 71.65 at the end of June, a roughly 1 percent decline month to month. Yahoo (NASDAQ: YHOO) is in the same stalled boat, with 14.37 at the end of June, a zero percent change from 14.43 percent the month before.

But for SEO consultants and search advertising buyers looking to evaluate the numbers, it may still be too early to see the changes in share as part of a larger trend.

For one thing, there's the fact that comparisons with other Web analytics firms remains difficult because their measurement criteria vary so widely. For instance, last week, analytics firm Net Applications, which tracks search share globally rather than just share of U.S. searches, reported little change in share for Bing after 13 months of general availability.

Net Applications found that, despite more than a year in use, Bing had only eked out a 0.43 percent gain from the 2.96 percent share it held after its first month of availability to the end of June 2010. After just over a year of availability, Net Applications found that Bing had reached a search share of 3.39 percent, compared to 84.96 percent share for Google.

The confusion doesn't stop there, either. For example, analytics firm comScore (NASDAQ: SCOR) has come in for criticism for how it counts "slide show" features recently introduced by both Bing and Yahoo that are counted as searches as users scroll through them. comScore has said it will change that in coming months.

Still, while Reynolds agreed that as long as Google maintains its commanding lead in search share, it's going to be "in the driver's seat," he also criticized the state of affairs that's led to so many differing, conflicting sets of data that does little to help SEO and e-commerce marketers make informed decisions.

"I think we need a better system," Reynolds said, describing efforts at comparing different analytics firms' numbers as little more than "apples to oranges."

Stuart J. Johnston is a contributing writer at InternetNews.com, the news service of Internet.com, the network for technology professionals. Follow him on Twitter @stuartj1000.

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