I think they would have to be smart marketers, very persistent sales people, and have superb customer service/follow-up skills. Do all that and I think it’s possible.
I think buyers’ realtors typically steer clients to inspectors so you have to make sure the realtors know you and love you, and that means pounding the pavement. Maybe even provide some commission to referring agents. Stuff like that.
I think experience in construction helps alot. An inspector isn’t only looking for things that are a problem now, but for things that could develop into a problem later and just knowing how things are built makes that easier.