It's hard to estimate with no data. Nintendo had never released any other mobile games and the few NES/SNES ports had modest sales (at admittedly high price points for mobile).
When it comes down to it, the game is closer to a fitness app than a Pokemon game and can be described as bare bones. The fancy accessory wasn't even available at launch. Many of the players are people who have not bought a Pokemon game in over a decade, or ever in some cases.
If there is one area I can solidly criticize Niantic for it is rushing the other region releases so quickly. It's clear the servers were already badly overloaded and they just started adding countries left and right. I know it sucks for people who live in those countries to have to sit out while the rest of the world is having fun, but it's really not much more fun to sit at the eternal loading screen because the backend is entirely on fire.
When it comes down to it, the game is closer to a fitness app than a Pokemon game and can be described as bare bones. The fancy accessory wasn't even available at launch. Many of the players are people who have not bought a Pokemon game in over a decade, or ever in some cases.
If there is one area I can solidly criticize Niantic for it is rushing the other region releases so quickly. It's clear the servers were already badly overloaded and they just started adding countries left and right. I know it sucks for people who live in those countries to have to sit out while the rest of the world is having fun, but it's really not much more fun to sit at the eternal loading screen because the backend is entirely on fire.