I don't know about anyone else, buy if my kids see a Toy Story 3 ad, they're going to click on it.
Yes, a lot of ads won't be clicked on. That's why it's only $17 ppm.
It's easy to say, I never click on ads, I skip through commercials, I change the station when ads come on, I never open junk mail, etc... But...enough people do that it makes it worth while.