That's a good question.
I started doing it after I got out of the military in 2000. I was medically released due to a service injury. One of the things they want you to do in your transition to civilian life is something within your skill set and capabilities. This prevents somebody who may be a pipefitter in the military and who wants to go out and be a brain surgeon from saying, “You need to pay for all my education.”
So this was something that was very marketable for me.