PBS will begin doing something it has never done before: interrupting its shows with promotional spots.The public television network announced at its annual meeting last week that, beginning in the fall, it will run spots for its underwriters and for other PBS shows four times an hour during two of its shows: "NOVA" and "Antiques Roadshow." That's a break from PBS' current policy, which is to run those promotions at the beginning and end of the hour but never to interrupt a show once it has begun.Public media site Current made this graphic showing how the changes will affect the programming:Read More...