Pico_Train - 5:01 pm on Apr 18, 2008 (gmt 0)

The results we show you are based not only on what we know of the Web, but also what other people have searched for.

That's toolbar data is it not? Not necessarily "related searches". And I'm sure it can be stretched to include something along the lines

"but also what other people have searched for and how useful it was to them" - length of stay, further deep clicks, back button, close browser,... you name it.