1. C&B revolver shooting is often associated with muzzle loading clubs. If there are any local BP clubs, make contact with members and ask if you can refer people to them to help out both their club and your business. It serves a mutualistic purpose. Promoting a muzzle loading club also promotes your business. Help them and the chances are that they will help you.
2. If no muzzle loading clubs exist in your area, consider starting one. It doesn't cost much to become affililiated with the NMLRA. It doesn't take many people to start a club. They can then began to pool their efforts and resources to find and/or lease a place to shoot while meeting at the houses of members or at a sponsoring business.
I've seen hunting clubs get off the ground that way, and there are creative ways for new clubs to raise money and begin having activities and making their presence known in the neighboring communities.
Even if there are only regular gun clubs in your area, if there are C&B shooters who are members of those clubs, why not ask them if they would be willing to help introduce new shooters to the sport. Why not ask them if there's anything that you can do to help them in exchange for introducing others to the activity?
3. I know of a defunct muzzle loading shop owner that was also involved in organizing shooting events on his private property for the muzzle loading club that he was a member of as well as for members of the general public that wanted to participate. Of course participation fees were collected to pay for prizes and expenses like targets. And because he also had a shop on the premises he sold powder, ammunition and supplies.
He had plate racks and metal silohuettes, turkey shoots and also held .22lr single action revolver shoots.
It helps if someone in the community organizes and holds shooting events to create a practical use and demand for the type of shooting and the guns that are being promoted.
Many folks don't know how to shoot C&B pistols, don't have a reason to shoot or buy them, and don't want to shoot them alone or learn to all by themselves. If an individual or club organizes events then people would be more inclined to participate and invest money in black powder guns.
4. A business owner can promote a knowledge base about the C&B sport and everything that's involved with shooting them.
Providing people with reading material, like copies of related magazine articles or a list of websites relating to BP and C&B shooting will increase the chances that some people will learn and research about the sport further on their own and will even consider taking up the activity soley as individuals.
For instance, a majority of smokeless shooters aren't aware of conversion cylinders and cowboy action type shooting events. It might be growing sport in some geographic areas and among some shooters, but not universally where there isn't much exposure, or promotion of events.
Even inviting individuals to come and shoot your own personal guns can spark an interest in individuals to take up the activity.
That's how it was for every shooting activity that I became involved with over the years. When that invitation doesn't occur, then sometimes interest can be sparked on line, but that requires more initiative on the part of the previously uninterested indivdual. Whereas a personal invite can arouse interest simply on the basis of personal contact.
People often respond to a stimulus. But that still requires stimulation of some kind, and someone to provide it.
You stimulated this thread, so maybe you can stimulate some individuals in your local area too.