When Warner Bros. produces an episode of "Friends" for NBC, how does WB "give" that episode to NBC? Do they send it over a satellite link? Do they send a DVD or DAT? Taking it a step further, how does NBC distribute that episode to its affiliates? I would think via satellite. But does NBC send each show in advance so that each affiliate can insert its own commercials? Or does NBC just send everything live and the affiliates can do real-time commercial insertion? Thanks!