Because it was long thought that few people would watch lengthy televised political messages, most televised political advertisements, like commercial advertisements, took the form of short messages  Last year, however, one candidate produced a half-hour-long advertisement  At the beginning of the half-hour slot a substantial portion of the viewing public had tuned in to that station
Clearly, then, many more people are interested in lengthy televised political messages than was previously thought
The half-hour-long advertisement was widely publicized before it was broadcast.