It would perhaps also drive up orders early in the cycle, as people can't wait until the last few minutes when they see a project has been funded.
Personally I think the simplest option would be allowing a 10% "overshoot" fund, and beyond that the project automatically closes to new backers - this should ensure that despite the various reasons why the money wouldn't come through from individuals (credit card rejected, etc), a funded project would get it's full amount.
It would perhaps also drive up orders early in the cycle, as people can't wait until the last few minutes when they see a project has been funded.
Personally I think the simplest option would be allowing a 10% "overshoot" fund, and beyond that the project automatically closes to new backers - this should ensure that despite the various reasons why the money wouldn't come through from individuals (credit card rejected, etc), a funded project would get it's full amount.