[jfruh]

I believe that you're not actually allowed to make up the difference under Kickstarter's terms of service. One of the points of the system is that it's supposed to be vaguely like the original Groupon idea -- you only get paid if you get enough pledges to meet your goal. (Backers only have their credit cards charged once the project meets the dollar amount you've set.)

In practice, of course, there are ways around this. Payments all go through Amazon's system, and I believe that they enforce this rule by just making sure that none of the credit cards for backers are under the same name as the Amazon payment account. If you just get a friend to pay for the difference and then write them a check for the amount you could get away with it.