Again, if there is anything we can learn from how the mobile gaming landscape looks today, it's that you shouldn't charge for your actual game. As popular as Super Mario Run has been, it has only grossed $53 million thus far. That's nothing to sneeze at, but it's also only 1/20th of the $1 billion that Pokemon GO has earned for Niantic. That's gross, not net, but you get the point.
While there certainly aren't as many players now as there was at launch -- hopefully not because they're all walking into traffic or off cliffs -- the game continues to gain new features and continues to print money. It went from a peak of about $18 billion a day to about $2 million a day now. For the record, this also makes Pokemon GO the fastest mobile game in history to reach the $1 billion threshold.
If you're already itching for the next big thing, Fire Emblem Heroes from Nintendo is available now for both iOS and Android devices. The mobile version of Animal Crossing has been delayed for an indeterminate amount of time. If that implements a similar location-based paradigm as Pokemon GO, I think Nintendo could have a real money-maker on its hands. Or bells. Animal Crossing uses bells.