I've often thought the same thing since becoming a full time freelancer, the talent agency model. The problem to overcome is that, much like most recruiters I've dealt with, it's hard to find someone who isn't a technical developer to understand how to fill a technical developer role. There's a lot more complexity to understanding the work from the outside than there is understanding the work of say an actor. I no more want someone representing me who's saying "ok I have a guy here who has HTML, PHP, Javascript, and CSS, and I see you have all of those on your job requirements, this is a match right?" than I like hearing the opposite from a recruiter. Essentially you're going to need to find developers who want to do sales, a tough find if I've ever heard one.