If 500 people are willing to pay $10 for a piece of software, a developer has two options: 1. Make it on your site for $5000 (minus your cut) and feel good about themselves; 2. Make it themselves, sell it on the web for $10, and make much more money. So much for others' incentive to produce your product.
It's a bit of a different model... on this site, a designer can see what they can make and sell for $5000. That is, "write a program, make $5000". As opposed to "write a program, make a website, figure out a way for people to find out about it, wait for money to trickle in".
Our cut for open source will be zero, and for commercial projects small. We're hoping the advantage of using microPledge will be that it's a central location people know about and will build up trust in. And also that the developer can focus on his project rather than on building a nice website with pledging functionality. (Our site's much more than just a SourceForge donate button -- but you'll have to wait and see. :-)
