I always thought KOA was an orginazation built at the campground owners level, and campground owners were buying into a franchise. you had to meet a standard. It includes the reservation system and I have a feeling also has some control on the business model etc.
I believe Good Sams was a system built on a business model where some business made a fee based club of campground users. Than they get campgrounds to pay dues to use the good Sam name to advertise.
I know woodalls also used to have a business where they would get the campgrounds to pay to be listed in the book, then sell the book to the campground users.