Bundle Dragon appears to be the open platform version of Humble Bundle - not that they're directly related but, conceptually, they have much in common. You can check out an example of what they're doing with The Game Music Bundle - highly affordable bundles of music with an even more rewarding tier of goods if you pay a little more. There's even a competitive aspect to it where if you are the top contributor at the end of the run, you receive even more rewards. I think I can get into this idea!