Eighty years ago, the January 16, 1945, issue of Broadcasting put forth this idea that apparently never went anywhere.  Suggested by one Joseph R. Spadea, the idea was that instead of carving up radio time into blocks of 15 or 30 minutes, blocks of 10 and 20 minutes could instead be used.  The author noted that some 30 minute programs seemed to drag on a bit too much, and this could tighten things up.