You'd think now would be a more opportune time for that approach than ever, since so many stations double-run shows back-to-back. But I swear I've read before that stations prefer two consecutive half-hours to one solid hour, though the reasons for such a preference elude me.
Two separate shows' worth of ad sales as opposed to one?
It was my experience from working in advertising at a couple TV stations that stations are usually selling the hours and not by the half hour, at least on a local level.
Now, WGAL in Lancaster, PA for instance, they are currently airing news at 12 noon followed by Millionaire at 12:30pm. Those two get sold separately because they are different audiences. Advertisers may want to have their ads run in News but not game shows, or vice versa.
But if it's a double run of Judge Judy or Feud or whatever, the assumption is that it's the same demographic audience watching over that whole hour, and when a local advertiser buys that show, their ad could air in the first break at around :07 after the hour, or after the second show concludes.
This may be completely different for national ad sales; I don't have any experience in that environment.
There's also some efficiency built in for a double-run show that airs last year's repeats in the second half hour; stations can charge the same ad rates for both the new and the second-run shows.
