For years Netflix has used their one week trial, give a friend two weeks trial etc as a way to let folks check out their service without a huge cost. And it's probably been rather successful.
But today they have started something a bit different. They've borrowed a play from iTunes' book and offered a pilot for free. This is a trick often used with new shows that will sell via Apple's online store, with the pilots sometimes appear weeks before the show does (and in the case of Mockingbird Lane weeks before the show was ultimately cut before airing at all).
Netflix is copying this trick as a way to debut their new Netflix produced show House of Cards. This remake of the British series stars Kevin Spacey doing what he does extremely well, playing a guy that looks like sugar and spice and all things nice but is as snakes and snails and puppy dog tails as they come.
It's pretty clear that Netflix is hoping this move will drum up eyeballs for the show and for their Watch Instantly service. Time will tell if it does. Or if the move will be enough of a success that they consider more freebies in the future.