Experian Hitwise, latest data shows that Google accounted 69.67% of all U.S. searches conducted in the four weeks ending Jan. 1. Bing-powered search received 25.77%, with Yahoo! Search and Bing receiving 15.17% and 10.605, respectively. The remaining 70% search engines in the Hitwise Search Engine Analysis report accounted for 4.57% of U.S. searches.
Bing and Yahoo! Search achieved the highest success rates in Dec’10, meaning that for both search engines, 81% of searches executed resulted in a visit to a Website. Google achieved a success rate of 65%, up 1% over the previous month.
Shorter search queries — averaging one to four words — increased 1% from Nov-Dec’10. Two-word comprised the majority of searches, amounting to 24.26. Longer search — five to eight words — were down 4% from Nov-Dec’10.
[Source]