Patent number 20070033102 uses face-recognition webcams to tell if users are paying attention to the advertisement. If they don't, then the software will disable or repossess the computer.
The patent says that it can make sure that paid advertising is watched. It involves asking users a question about an advertisement or requiring data about the advertisement to be entered.
The idea is that when the advertisement is correctly answered then cash will be sent to a user account.
The big idea is that schools will make a bit of cash on the side by forcing kids to become marketing guinea pigs and the patented technology will make sure they obey.
You can see the patent here. ยต