Also see:

• Hitwise’s data: “Google Holds Steady at 66% of US Searches, Ask.com Share Up 19% YOY“
• comScore’s chart of search share data: “Online Search Share, November & December 2007“
• Additional info from comScore: ”Searches Jump 9% in January, Only Yahoo Loses Share“ 

Nielsen Note: Effective with October 2007 reporting, Nielsen Online has made several enhancements to its MegaPanel service. These enhancements include more granular reporting, increased accuracy, an expanded Internet universe and more advanced tracking. Because of these methodology changes, however, pre-Oct. ‘07 results from MegaPanel-based products, including MegaView Search and MegaView Online Retail, cannot be trended with more recent results.