Let me give you an example. I teach programming privately. People pay me $100/hr. Some of them found jobs thanks to my lessons. Some of them realized it's not for them and they didn't waste tons of money and time. And I've been doing this long enough to say there's a demand for my services and people generally like it. I don't grade them, I give them useful feedback on what should they improve and if they should continue. My primary goal is their success, not some stupid grade. Market works great if you apply it right.