Television maps well to the tabletop roleplaying experience. Episodic stories fit the single RPG session, while the "season arc" that structures most modern dramas works very well as a map for a whole campaign. NPCs in your game become the "supporting cast" of the 'show', and locations your characters visit frequently become 'sets'. If you have a game that is a success, you're free to run another "season".
You can push the "TV-ness" of a game by adding elements like a theme song, to start out every session. Players can bring their characters into focus by choosing real-world actors to "cast" in the part.
Finally, this framework has the advantage of being familiar to almost every player at the table. There are lots of players who might not know the jargon and high-level rules associated with GMing, but they've probably seen their share of television shows. They are very likely to know all the conventions and specialized language associated with episodic TV intimately. And this gives the player and the GM a great starting point to talk about building a game.
As an aside, I am well aware that others have followed the same chain of logic and borrowed from TV as a framework for a game -- Primetime Adventures being the best example of this. If you haven't played PTA, you should.
With television in mind, the basics of the campaign model become clear: a short run of sessions (6-10 are ideal) form a "season" of the game, with each session having a self-contained (episodic) story with a beginning, a middle, and an end. The season also has a "story arc" over the course of 6-10 episodes, and brings things to a conclusion at the end which provides a sense of closure. If the game ends there, players should be able to walk away satisfied that everything important that was to happen in that game did indeed take place.
It is especially appropriate to think of the structure of each episode in terms of the Three Act Structure which informs modern screenwriting. This means that each story has an initial Setup, or Introduction, which establishes the initial situation; this is disrupted by a Turning Point which changes things up and sets the stage for the conflict. The body of the episode should be about the characters' Confrontation with whatever the issue in the story is. Finally, there is a Resolution of the situation where the conflict is resolved and the characters are changed.
This also maps to the level of the season (or campaign) in a sensible way:
The body of the season's episodes focus on individual characters. In the above model, we're assuming that you have four players involved in the group (which I have most often found to be the case). The second Act develops the characters by bringing them into sharper focus, giving each character a chance in the spotlight. The arc story develops in the background of these episodes, and should be brought to a head before the last episode of Act 2.
The "season finale" should confront and resolve all of the most important conflicts that are in play.
To be continued...