I agree with Pat Hartman, leeds are not worth very much but sales are.
You could set up a forum which people pay per lead or pay a fixed monthly fee to access the leads. I don't really like this idea as this the great thing about this site is the free information exchange, having the same peolple competing commercially may affect this.
I think that your best bet is to deal with the people who have been posting here for a long time, pass them the leads for free and agree a % scheme with them if paid work was obtained, obviously this would have to be a trust based relationship. I use the same deal in my industry , when I come across work for other disciplines I refer associates that I know and they price a fee or % into the job for me and vice versa.
My real job is as a mechanical engineer in Oil, gas and power generation. I get heaps of requests from service contractors, for such things as risk management db's, inspection management db's, fabrication management db's etc. I do not have the programing skills to do much about this. I do however have the engineering skills and knowledge of codes and standards to develop the mathematical models required.
The members of this site are pretty much split into two groups. Those who know how access works and those who know what they want access to do for a real world situation. A pretty good combination probably.
I would be interested in following up some of the requests I get and working with expert programmers on a mutually beneficial basis. An exchange type forum of this nature on this site may be worth exploring.