I always imagine the interaction with supply (quality freelance developer) and demand (company needing work done) to be like this:
Company: "I need great freelancers!" Dev: "I'm a great freelancer! My rate is $100/hr [or whatever]!"
[Company interviews Dev, sees prev results, feels happy w/Dev]
Company: "Great! We'll pay you that for the first few days on this platform, then engage you for long term projects off the platform. That way, we don't have to pay Matching Site the finder's fee."