My favorite Linux web audio show is LUG Radio, and on the most recent episode the presenters reprised the idea that open source software users might (not must) reward development of some projects by funding software developers. So that some few people might not be stuck as suckers providing a public good, the presenters mentioned a couple of web sites that had a mechanism that allowed a group of people to fund a project provided enough funders put up the cash. If the appeal was incomplete within a predefined time window, everyone who contribted got their money back.
"What a great idea," I thought. And what a remedy for the "sucker factor" -- the flip side of which is known as the "free rider effect." (Which also explains why anti-military tax boycotts are unfair. Principled, perhaps, but unfair.)
I'm not a libertarian, but I have wondered why I'm asked to fund projects -- back to the UUA now -- that could be self-funding but for which no mandate or future support has been cultivated.
Or you can just read this article at Wikipedia.