Maybe the idea of using Bing for search engine optimization (SEO) isn’t such a big deal after all.

While many have touted the importance of a Microhoo deal which would give Bing and Yahoo a significant portion of the search engine market and make the combined entity more important in the world of search engine optimization (SEO), it seems that Bing has hit a snag.

According to figures released last week from StatCounter, Bing saw its market share in the U.S. and around the globe drop for the first time since it was unveiled earlier this year. In what may make matters worse for the Microsoft/Yahoo partnership, Yahoo also saw its U.S. market share drop more than a full percentage point in September.

Both Yahoo and Bing’s drop appears to be a direct gain for search behemoth Google. According to StatCounter, a combined Bing/Yahoo search presence had 20.14 percent of the U.S. search market in August, compared to 77.83 percent for Google. But in September, Yahoo and Bing saw their share drop to 17.91 percent while Google increased to 80.08 percent.

"The trend has been downwards for Bing since mid-August," said StatCounter CEO Aodhan Cullen. "The wheels haven’t fallen off but the underlying trend must be a little worrying for Microsoft."

However, it may be too early to count out Bing as last month Nielsen reported that the Microsoft product held 10 percent of the search engine market.