> the sales person knows exactly how much money they bring in
I agree this is the key factor. Any job where a person can argue a clear, direct, measurable link between their work and profit is a job that can be paid based on financial results. Other jobs where you see this: financial traders, consultants with direct client contact.
To take the other extreme, look at teachers. They have the potential to generate huge value based on how effectively they develop society's human capital. Unfortunately the effects of a single teacher are so noisy and indirect that it's basically impossible to measure their performance. The lack of firm data is why the debate about teacher compensation is so fraught.
I agree this is the key factor. Any job where a person can argue a clear, direct, measurable link between their work and profit is a job that can be paid based on financial results. Other jobs where you see this: financial traders, consultants with direct client contact.
To take the other extreme, look at teachers. They have the potential to generate huge value based on how effectively they develop society's human capital. Unfortunately the effects of a single teacher are so noisy and indirect that it's basically impossible to measure their performance. The lack of firm data is why the debate about teacher compensation is so fraught.