Lately I've been watching some old trailers, and I was taken by how much they used to include actual scenes from the movie they were selling. Nowadays you get a rush of images - usually fading in and out of black more than they're actually visible - set to a BWAHHHMing soundtrack. You can't tell what the fuck you're looking at.
But the trailer for The Conjuring is quite old school in the way it sets up a scene, plays out the scene... and then pays off the scene. It's simply a GREAT trailer, and it takes its time to earn scares. This is simply a great trailer, and I bet it kills in theaters, where audiences are used to pulsating waves of images washing over them.
God bless you, Warner Bros, for putting out a trailer that is actually good.