PROGRAMS are television's bait. They lure viewers to millions of TVsets, and, in the normal way of things, those viewers are in turn "sold"as rating numbers to advertisers hoping to reach the viewers with commercial messages. According to one network head of research, as little as one-tenth of a rating point over the course of a year can be worth as much as $30 million in revenue.! Given programs' incredible value, the business of programming-the choosing and scheduling of programs-is crucial to the television industry, and the networks have developed a panoply of strategies for capturing audiences.