In my recent post about Google search I cited the horse race on to own the search term sustainability using organic search and my experience with search results starting to vary based on my geo (Portland) and without me stipulating a geo search parameter. I cleaned by cache, google cookies and took my address information off Google profile and did this search today and nothing much changed. But then my friend, Barry, sent over an article from the March 2010 issue of Wired entitled Inside the Box. It’s all about Google search. And herein I read:

There is an opt-in feature that uses someone’s search history and location as a signals to determine what kind of results they’ll find useful. (This applies only to those who sign into Google before they search.)

I wonder where I opted-in? And I never notices whether I’m signed in or not. Will check on this.