Buying an "option on probability"

From an article in NYTimes on a patent application filed by Philips-

James Boyle, a law professor at Duke University, said that broadcasters offer a program knowing that only a fraction of the audience watches the commercials. Advertisers, he added, buy nothing more than "an option on a probability," and the viewer is no more obligated to watch every commercial than a driver is obligated to read every billboard.