I think he's referring to "cognitive surplus", not opportunity cost as you seem to imply. So for example, if these guys were paid to play games which solved pro

I think he's referring to "cognitive surplus", not opportunity cost as you seem to imply. So for example, if these guys were paid to play games which solved problems for other people, or were given jobs that used similar skills they have been cultivating while playing these games. Think perhaps a form of Mechanical Turk or SETI@home.