Microsoft's efforts to promote and revamp Bing appear to be paying off, as the search engine has enjoyed steady gains in the U.S. market since its launch in June 2009.

Microsoft's share of U.S. search traffic increased to 11.5% in February from 10.7% in January, according to the most recent figures from market watcher comScore. Yahoo, currently the number two player in the market, saw its share fall from 17% to 16.8% over the same period.

Market leader Google, meanwhile, enjoyed an increase of just .1%, from 65.4% in January to 65.5% in February, comScore said.

Microsoft's gains in search are in part due to its steady efforts to publicize and upgrade Bing. The company this week announced yet another slew of enhancements to the search engine.

Most notable is an upgrade to the Quick Tabs feature, which delivers results based on what the search engine believes is the intent of the user's query. For instance, a search on "Barcelona" yields tabs that give users one-click access to weather, news, and travel information related to the Spanish city.

Going forward, the information delivered through Quick Tabs will be displayed much more prominently, said group product manager Todd Schwartz, in a blog post.

"Over the next few months we are going to test some new design concepts moving Quick Tabs functionality to the top of the page for 1-click access to our most robust, visual, and organized pages," wrote Schwartz.

Microsoft also plans to enhance Bing's ability to deliver real-time information. For instance, a new feature will connect users who search for a particular news source, such as USA Today, not only to the main site but also to links to the most popular stories, based on what's being shared across social networks like Facebook and Twitter at any given time.

Additionally, Microsoft unveiled a new application this week that integrates data from the location-based social networking service Foursquare.

"Let's say you're travelling to New York City for the week, but you don't know what's hot in Greenwich Village. Selecting the foursquare Map App in Bing Maps, and zooming into to Greenwich Village will get you tips that show you what locals are saying about the hot spots in that area," said Schwartz.

Yahoo, for its part, may be suffering from the perception that it's abandoning the search market, as it will eventually outsource search on its pages to Microsoft under an alliance the two companies struck last year. That will further boost Microsoft's share of the search market.

As for Google, its dominance of the search advertising market is drawing scrutiny from antitrust regulators in the U.S. and Europe, and any efforts by the company to grow its stake significantly beyond the 65% mark could spark regulatory action.

Indeed, many of Google's recent moves to grow revenue come not from attempts to further build search share but from endeavors to exploit new markets like e-mail and cloud-based software such as Google Apps, which offers e-mail, document, and calendar services.

While month-to-month comparisons show incremental shifts in the market, the longer-term view indicates that Microsoft is gaining significant search share while Google stagnates and Yahoo fades out.

Bing launched in June 2009, when Microsoft's share of the search market was just 8.4%, Yahoo's share was 19.6%, and Google held a 65% stake. ComScore's February numbers therefore indicate Microsoft's share of U.S. search traffic has increased 37% since Bing went live, Yahoo's share has declined 14%, and Google has remained flat at the 65% mark.

The upshot: Microsoft is likely to continue its search gains, at least in the near term, while Yahoo struggles and Google's increases taper off.

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