[InclinedPlane]

Kickstarter has a mission: to enable crowdfunding of projects. Within that mission they've built tools to facilitate that as well as created guidelines and limitations on projects. All of this is designed to create and enhance trust.

As for payments, a big issue is overhead, chargebacks, and failures. Using amazon payments may insulate kickstarter from some of that.

One may ask why kickstarter isn't just geocities with easy to add paypal buttons everywhere, but I think it's obvious that such a site would probably not be as successful as kickstarter.

Edit: some stats: during 2012 Kickstarter had about 18k funded projects with a total of nearly a third of a billion dollars in funding. Indiegogo doesn't release stats for the total amount of project funding in a year but it's quite evident that it is far lower than kickstarter's numbers.