When the Amazon mTurk first came out in 2005, not a lot of people knew about it. I read about it in a thread on the Something Awful forums and signed up; the idea was basically a marketplace for microtasks like transcribing an audio clip or translating a paragraph of text from a German medical book or whatever. Most of these tasks were usually not worth the effort... Except for the ones where you had to look at nine pictures in a grid and check the boxes that had the McDonald's or the trashcan or the gas station or the stopsign in it. Sound familiar? Anyways, I got something like half a cent for each proto-CAPTCHA that I completed correctly. Eventually someone made an Opera plug-in that allowed one to finish hundreds of these tasks per hour--- some were making as much as $40/hour, or so they claimed. Everything got paid out at the end of the day in Amazon Gift Cards (although I vaguely remember a 30% premium on PayPal withdrawals). At the time, I was in eighth grade.