"Unfortunately though, the people who use IE6 are the same people who click on "You won $10,000!! Click on the monkey to claim" adverts"

Um, not necessarily. Some of us are stuck on corporate machines that prevent you from running anything else. My back of the envelope guess is that this contributes to at least 25% of IE6 use.

I would guess significantly more that 25%. I used to work at a huge consulting company that still ran IE6 and was only recently looking to upgrade. I consulted for a government agency which was using IE6 and had no intention of upgrading soon. In fact, IE7 is banned by some government agencies.