Not sure what you mean by this...
Game Of Thrones is adapting a book per season. You're guaranteed an entire books worth of story per series. In every book....stuff happens. Compelling. Interesting. Makes you keep reading.
Shows with one good idea, like Lost, aim to drag that $hit out till the money stops rolling in.
When writing a pilot for a show you have to include what is referred to as a bible, which will focus on the characters, relationships and back story rather then explaining a resolution to the crisis of the show (i.e why the f#ck are they on the island). A good writer already has the entire series planned out (Prison Break season 1 is a perfect example).
This is why seasons of shows like Flash Forward, Prison Break, Heroes, The Event etc die in their ass when they're only on for ratings. They didn't give a toss about the story and assumed people would just keep tuning in for years to get an answer.
