Because none of us are internet noobs. Internet advertising is big business. I've seen people think that they won a free iPod because they shot a baloon or some dumb shit in a pop up window and so they go and fill out all the shit. I don't know. As long as one out of every 1000 people actualy buy something they are proably still making money.
Twenty-eight days... six hours... forty-two minutes... twelve seconds. That, is when the world will end.
Some people have very poor mousing skill, and thus believe that everyone else does, too. That, or their computer is so slow that it looks like they're jumping arround randomly. Generally, though the people that click on those are the same ones who have their computer so full of malware that it barely moves; I'm sure you know of at least one person like that, so...