Agreed on all points - it's a chicken/egg situation to be sure up front. It's something I've thought of doing just because of my circle of contacts - I know many fairly well (probably 5-8 pretty strongly), know their strengths, know what they'd like to be doing, and I get calls from both recruiters and companies looking for people with XYZ skills/interest. I'm not sure it's enough for me to do full time, but it's made me think more about this issue, and the state of the industry.

Getting the 10% out of some people would be hard - I guess you just wouldn't use them as clients(?). Would you collect up front? Weekly payments? I don't know many developers who can easily just hand over $8-$10k in a lump sum, so you'd probably have to collect over time, and if they're not good with budgeting, that's a whole other problem.