When Kickstarter started, the types of payment logic they needed (user approves payment now but don't execute it until later; user feels like they're approving

When Kickstarter started, the types of payment logic they needed (user approves payment now but don't execute it until later; user feels like they're approving one payment, but it is split between multiple recipients (Kickstarter and the project owner)) weren't supported by PayPal, but were supported by Amazon Flexible Payments Service In 2009, PayPal rolled out a set of very similar API's that would allow them to do these things (see http://x.com http://x.com). I would guess that the fact that they haven't made the switch is just a matter of inertia, the difficulty the transition might present, and having more important things to work on, but I'm not intimately familiar enough to know if there are other reasons they might be staying. I do know that a friend of mine had a startup that started on FPS but was very, very eager to switch to PayPal when X came along because FPS presented so many problems. They were a lot smaller and less wedded to the platform, though.