tedster - 12:02 am on Aug 24, 2012 (gmt 0)
I wish we had that kind of answer. It may not be Chrome data or toolbar data, or even Google Analytics but it seems to me that Google accesses user engagement from somewhere. Free wi-fi? Buying click stream data from a big ISP or two? Who knows.
I think my opinion on the issue has been distorted a bit by several conferences where Matt shared the stage with Bing's Duane Forrester. Duane has given some extensive comments about they're user-data signals that sound like browser data to me (did the visitor scroll, hover on a link, bookmark, etc? During those sessions, Matt did not chime in for Google's POV.