probably just by pressing the power button on your machine. If you expect to have revenue; also expect some of that revenue will be appropriated by lawyers.
Some of these courses have "certificates" awarded for fees; and said certificates are the entry point to some businesses; just like the steep steps in front of the building.
When I was in school the professor said something about interest rates and opportunity costs that was more algebraic than arithmetic; but I guess that is all academic.
"Another theory is that the dollar sign may have also originated from Hermes, the Greek god of bankers, thieves, messengers, and tricksters. One of his symbols was the caduceus, a staff from which ribbons or snakes dangled in a sinuous curve." Thanks for the downvotes.