I am a web content creator. I am not good at design, legal issues, etc. I imagine I'm not the only one.
I wish you had professional service listings: - web design - consultants (business, advertising) - legal services (the is the best place on the web to advertise legal services to webmasters, right?) maybe: - accountants specialized in our field - angel investors/VCs
I recommend charging monthly, not "per ad". Only real professionals that seem to have their act together.