Where I live (Denmark), the real estate guild has captured the market by building the de-facto listing portal and only making it available to registered brokers. Sounds great if the US portal (MLS?) is available to all listings.

For selling a small plot of land I got so angry about the fees for nothing that I paid an obviously rogue broker to proxy-list the thing. This guy was charging half of what the other brokers were (still way too much), and did not do anything except upload documents from me.