In poker it's known as slow rolling your hand. You let out a little information at a time, your opponent thinks you're bluffing and raises the stakes, and then you show your hand and crush them.

Matt Drudge did the same thing with the Lewinsky story in the 90s. He let out a little bit of the story at a time, the media acted like he was a kook, then he would reveal more of the story and make them look like morons.