Originally Posted by Fat Cobraroll
I think at some point (which me may already have passed) it will become so repetitive that the original fans of the series begin to lose interest entirely, opting to quit when they still have fun and unspoilt memories of the franchise.
However, while that indeed happens, every generation serves to drag in new fans to the series. Those fans will stick around for a generation or two, before they eventually outgrow it. But by the time they quit, new ones come to take their place, and so on.
Consider the great American comic book heritage, for instance. The characters are 70+ years old, yet still attract new fans. Those who read the originals might think the direction the franchise has taken and the choices done by the executives have completely screwed the entire spirit of the series, while younger readers are unable to identify with the original series their grandparents loved. Either way, the franchise survives and is popular. Pokémon may still have decades ahead of it before discontinuation - even though that might mean a gritty reboot now and then.
I get the coming and going of new and old players. I'm an original player that started playing when I got Blue for christmas when I was in like 6th grade and I still play today, and I still think the games have been great all the way through. Overall though, sales wise, the series isn't climbing anymore. It's kind of peaked and it's just riding it out. The numbers aren't bad by any means but generally in situations like this in gaming you don't get another large spurt of growth. I don't think the game is ever going to be larger than it's been before, and eventually it's just going to fade out. It's inevitable of practically any game franchise or long standing 'thing' in general.