I wouldn't do much good at the moment, but it could be a step in a good direction. To promote a service, you gotta target the buyer, not other sellers. However...if you were to create a page clients could visit and post classifieds like "Engineer wanted for my project", that might pick up, depending on your plan for drawing people to it. Ideally, we want more people posting for 'mix engineer needed' than there are engineers on the site
I would think about this though, as if it were a building with limited real-estate and floor space. I would pull that section off if it doesn't pick up, because any portion of a website forum that unused works against you.
If you do this, I'd strongly recommend forcing the poster to clarify if the job is paid or not. I wanna know their budget up front. That can save everyone a lot of time. If you allowed the studios to solicit services, I don't think this group will relentlessly spam the classifieds. However, I noticed that film and video game forums have trouble with this, and have had to enforce strict rules regarding what audio engineers can and can't post.