One ventures into a market hoping it would be profitable. It does not, so one tries to "train the customers". That letter probably didn't increase sales. But

One ventures into a market hoping it would be profitable. It does not, so one tries to "train the customers". That letter probably didn't increase sales. But this guy and his company managed to hang around making revenues until they were approached as a partner by some large company that knew how to get customers to pay through their noses.