The key is that, unless the project reaches its stated goal, the money you pledge is safe. So if it’s looking for $10,000 and only raises $1,500, you get your money back. Pretty spiffy.
Purple Pawn has taken it upon themselves to do an interview with a bunch of different game designers who used Kickstarter to fund their games. They asked questions of both people who were successful in making their goal, and those who were not:
For those of us in the RPG hobby who might be looking for funding for a gaming project (and remember it doesn’t have to be the whole project; you could easily do a Kickstarter campaign to raise money for, say, artwork or the cost of printing) this is an invaluable insight into the way Kickstarter does, and doesn’t work.
No idea why they didn't interview Greg Stolze. He's honestly the first guy that I think of when I think Kickstarter, since the old Ransom Method basically proved that crowd funded games could be viable.