Wow. Pratt's obsession with Kickstarter "ripping off" Fundable is especially silly considering that both are essentially variants of Kelsey and Schneier's Street Performer Protocol, published in 1998 [1]. (That paper is not even the first instance of the basic idea, just one of the most well-known.)
Edited to add: I'd be really interested to see one of these sites implement the Rational Street Performer Protocol [2], which essentially means that each donor pledges matching funds ("I'll donate $X for every $Y that anyone else pledges, up to a maximum of $Z"). This gives individuals a stronger incentive to pledge more; the hard part is coming up with a simple explanation that first-time users will understand.