I was pretty sure that Elite 4 was going to be a flop when the Kickstarter opened. They had nothing to show for it other than some flat shaded prototype in the background (check the first KS video!) and Mr. Braben talking.
Star Citizen already had a carrier and several ships, in game, with FPS walking around. CR's push for "cinematic experiences" and him playing in third person was what made me hold off of SC initially. Then the ED alpha happened and when I saw those first youtube videos of actual gameplay by lots of people, I knew I had to have that. The first Elite Alpha was incredibly focused and polished.
BTW another game that has a similarly polished alpha/teaser is Overload. These guys also know what they're doing. And they're promising a true successor to Descent - nothing more, nothing less.
Also I would want to bust myth about CR helping ED kickstarter. He was very conflicted over support to it, and most of SC backers said they aren't interested just a game, they wanted to buy ships. In short, they quickly disappeared, claiming SC will come in one year so why support ED in first place.
What carried us over big slump in the middle of KS was Drew biting a bullet and doing Kickstarter for his book. Then Kate followed. Then FD started to communicate more clearly. Rest is history.