If marketing to adults I'd publish one hardcover, max 256 pages, complete game, streamlined system. "Dungeons and Dragons" core rulebook one and done. Commercials/advertisements would focus on adults sitting around telling an exciting story. A nice game night with friends. Easy to learn, easy to play, unlock your imagination and take a few hours away from your regular responsibilities (children, career, etc). Sure, television and movies are fun, but don't you want to tell your own stories?
As a business model I don't know if it's any good. I just think if you say "Here's 920 pages of rulebooks to read first..." you'll have lost 90% of your intended market (adults, people over 25 for arguments sake).