I went to a franchise buyers convention once (it's a long story but I was going to set up a 7-11) and one of the presenters gave a bit of advice; "do what you know". It sounds simple but myself and most everyone else there didn't get it at the time but it means that if you're going to open up a buisness of your own, open it in something you know a lot about. Many years later I understand that advice; I don't know a thing about hair so it would make no sense to me to open a hair salon. My big haired wife knows squat about archery so it would be insane of her to open a bow shop. She would do well with the hair salon and I'd make a killing at the bow shop because we know about what we're in the buisness of. I always thought that my area needs a decent bow shop that has a good indoor range. All of the ranges in my area are kind of boring. It's almost as if they were an after thought addition to the store. I'd like to see a free range 3D range with more than just paper targets against a foam wall to shoot at. It would turn a casuel shooter into a serious archer who lives to shoot his bow.
I've also thought that a gun shop that had an attached skeet range would do very well by the Mississippi river. Especially if they offered a boat launching service for the duck hunters.
Or maybe a bar/pizza restraunt/campground in the UP of Michigan that was next to one of the big national forests. It could cater to famlies during the summer and hunters in the fall.
Use your imagination of what kind of buisness you'd like to see in the sport you love and do it.