Every time you watch the Gangnam Style video, Korean pop-star Psy makes 0.325 cents.
Interesting article from Quartz about the most watched YouTube video ever and a peak at the economics of YouTube. According to the article, Psy has generated $8M from 1.23 billion views, which works out to 0.65 cents per view. Apparently the creator of a YouTube video keeps about half that. Not a bad deal for Psy or Google.