Nintendo investors who thought they would score big returns after this summer's successful launch of Pokémon Go found that actual profits were more elusive than the colorful characters. Nintendo last week made it painfully clear that The Pokémon Co. and Niantic -- the developer of the popular mobile app that takes players off the couch and into the real world -- were far better positioned than it was to reap financial rewards. Much of that revenue potential lies in a wealth of in-app purchases designed to heighten excitement.