Originally Posted by GiorgosK

Google analytics are for you to see and improve

Google in similar fashion does its own collection of data as Spency says.

Do a search lets say "hello"
dig into the code for the first link


when you press on a link google knows about it.
if you return back to the search area (in a matter of seconds, knows that with cookies) and keep on going down the possible sites to visit, google knows you where not satisfied
(you bounced)

If you never return or return after a long time then you probably liked the site and it was relevant to the search you made !!!