Looks like Microsoft has finally surpassed Yahoo in search engine market share. From what Comscore is stating, Bing has overtaken Yahoo with 15.1% of the US web search market, all thanks to a drop in market share with Yahoo.
"Google Sites led the U.S. explicit core search market in December with 65.9 percent market share (up 0.5 percentage points), followed by Microsoft Sites with 15.1 percent (up 0.1 percentage points) and Yahoo! Sites with 14.5 percent. Ask Network accounted for 2.9 percent of explicit core searches, followed by AOL, Inc. with 1.6 percent.," Comscore stated.
Yahoo may have had a 0.6% traffic decline in just one month (November to December 2011), but Microsoft was able to jump on it and increase Bing's share. On top of that, Microsoft recently signed a deal with Yahoo that allowed for Yahoo's web portal to be powered by Bing search results. Microsoft has worked hard to boost Bing and make it a viable competitor to Google and Yahoo, but Google has been a hard enemy to defeat.
Despite all Microsoft has done, Google is still number one in search and Microsoft has yet to be even close to it. Reports even indicate that Microsoft should be concerned that as Android's popularity grows, so will the use of Google's search engine.