Early on, Microsoft's rebranding efforts of their search engine "Bing" was showing market share growth, but within the last month shows a 0.5% loss. Still, based on the comScore and J.P Morgan reports, MSN/Live/Bing's market share has grown from 8.5% in January 2009 to 9.3% in November 2009.
Yahoo! has started 2009 year with over 21% search engine market share, but has since declined to 15.4% as of November 2009. Most of the market share decline has been attributed to the elimination of the browser-toolbars bundled with a number of PC computer manufacturers. Within the last year, Acer has switched it's toolbar to Google and Hewlett-Packard to Bing. Back in April, the Wall Street Journal estimated the loss of toolbar deals could cost Yahoo! 15% of it's market share.