Whether clickjacking is an ethically responsible way of earning advertisement revenues is a subjective discussion and should not be discussed here.
However, it appears that quite a lot of popular sites generate "popups" when you click either of their links or buttons. An example is the Party Poker advertisement (I am sure many of you will have seen this one).
I wonder though, what kind of advertisement companies allow such techniques? Surely Google Adsense does not? But which do, and are they reliable partners?
Update: an example of an organization using clickjacking to earn advertisement revenues is The Pirate Bay. When clicking on a torrent link, advertisements of Party Poker will popup.