I'm a recruiter (used to be an engineer) and recently launched my own firm. This is something I spend a lot of time thinking about, as I find that the incentive structure created by the contingency model where the company is the customer encourages many of the poor behaviors that people associate with recruiting (spamming, cluelessness, bullying, etc.).
Do your clients talk to each other a lot? Work on projects together? I think I'd want to work on a project with someone before I referred a client of mine to them at a moment that I was too busy.
Also, what level of talent/experience are you looking for in your freelancers? How do I know if I meet the requirements :-)
The one caveat is that obviously demand varies based on the skill. Our dealflow is steadily picking up as our network grows and as we get press like this, but customers aren't exactly knocking down our door looking for Erlang hackers... yet.
(The bioinformaticist happens to also be a kickass iOS dev.)
That said, if you have your own dealflow for your skills -- no matter how obscure -- and are interested in our services beyond just sourcing gigs, we're happy to work with you.