Sometimes it seems like the easiest thing to market is knowledge and time. There are a lot of people out there who need to know how to safely handle a firearm and legally defend themselves; you will be providing a valuable service that might saves somebody's life.
Good luck in it!
I had a hippie roomate once who had to ask me to show him how a pump shotgun worked. He was in his mid twenties, and nobody had ever taken the time to show him how even a simple shotgun functions, much less how to safely handle one or how to aim and fire one, sad really.