This seems to be a good idea: Vidsense. A program working similar to Googles Adsense. Only difference: the context-sensitive input are little video clips. They are, of course, preceded by short adverts – 15-30 secs long. The clips are about 45 secs to 90 secs long. And the videos don’t start to play, unless a user initiates them.
This can be, of course be much more effective than Googles Adsense, as there is more than just text, but it’s (hopefully) not as intrusive as banners or rich media ads. And its relevant to the content your reading.
And you can also choose, if you don’t want X-rated clips, but only G-rated ones. (Other than that, you don’t have a choice).

Nice thing: you also earn money by a user’s click. Difference being: the click you need here is the one of the user starting the movie. And since the user doesn’t think the tool will take him off the current site (as it would be with Adsense), a click is much more likely…