bluntforce - 10:03 pm on Oct 2, 2012 (gmt 0)

@The_Fox
Google has publicly stated they do not use data from Analytics to alter search results for individual sites.

Google does use cookies to personalize results for up to 180 days when a person is not logged in to Google. When a user is logged in, there is undoubtedly more data accessible to Google. Up to 30% of my search engine referrals do not have a keyphrase(logged in user) so I'd guess Google does obtain a pretty good representative data sample from it's users.