Apparently, somewhere around 1% of the searches use that button - for a yearly loss of $110 million yearly - no adverts come up. It is controversial (sorta) - there was even a limited edition `I'm feeling lucky' boxers
>So you've got really good precognition skills?
No, I simply make my own luck. For example, up until recently I could search for "hotmail" and the "I'm feeling lucky" button would take me right there. Now I need to use the "live mail" incantation for the same result. It's a matter of going somewhere often enough that you know the search string that guarantees #1 on the hit list.
I don't use that button for general searches because I'm interested in all of the options for a non-specific search, not a single result. In other words, the "I'm feeling lucky" button is my bookmark list when I know the right search string. ;)