They wouldn't be paid if they weren't worth the money they were getting; the customers would rather keep their money. Lawyers: Do I really need to explain that

They wouldn't be paid if they weren't worth the money they were getting; the customers would rather keep their money. Lawyers: Do I really need to explain that they perform an important, valuable role? Drug dealers: Can't say much here. Drugs are tricky, economists call them inelastic, and they can make people irrational. Bankers: I sure like being able to invest my money and use it everywhere via EFTPOS Accountants: It's a hell of a drag doing taxes. It's very valuable to have someone do this work for you (if it wasn't, everyone would do their own accounting). Bottom line: determining value is a tricky economic/algorithmic question. Luckily, we have a price system, where people can set prices. If the customers pay that price, that's a strong indicator that the service is worth that much. It's not perfect (see bubbles), but it works pretty well on average.