I noticed both consoles had a similar amount of games for the franchise so I decided to compare the sales between similar games.

Note: Only retail sales considered, 3DS might surpass the DS ones if we had numbers on digital sales

FRANCHISE DEBUT

Pokemon Diamond-Pearl (DS): 18.25M

Pokémon XY (3DS): 16.14M

PREVIOUS REGION REMAKES

Pokemon Heartgold-Soulsilver (DS): 11.78M

Pokemon Omega Ruby-Alpha Sapphire (3DS): 12.65M

SECOND REGION IN THE CONSOLE

Pokemon Black-White (DS): 15.18M

Pokemon Sun-Moon (3DS): 14.79M

SECOND REGION REVISITED

Pokemon Black 2-White 2 (DS): 2.00M (at second week)

Pokemon Ultrasun-Ultramoon (3DS): 2.98M (as of second week)

SO, WHICH DO YOU THINK WAS THE MOST SUCCESFUL CONSOLE FOR THE FRANCHISE?

I think it's pretty tied, but amazing that Pokemon was just as (and in some cases more) successful despite a smaller install base.

I think the fanbase is pretty loyal enough to the point most will move over to the transition to Switch making the series just as successful on that platform. Not to mention the big potential opportunity for the growth of series. Being HD and also on a home console as well as a handheld will definitely be able to pull in a lot of old and new fans.

Talent lost

Might as well use official numbers

https://www.nintendo.co.jp/ir/en/finance/software/3ds.html

They're pretty much tied, with 3DS having the chance of winning in the end. It won't matter much anyway.

Regarding Pokémon on Switch, I'm confident it will reach 30m again.

Switch should handily beat 3DS lifetime, so I'd say yes.

3DS Pokemon will come out slightly ahead of DS Pokemon since it is still selling on the 3DS. What is kind of amazing is the inelasticity of Pokemon demand. As a whole, these 3DS consoles have been more pricey than the DS ones, but the Pokemon fans still came out to buy at least as many Pokemon games.

I don't think the $300 Switch price tag is going to phase Pokemon fans one bit.

You really think that? Pokemon hasnt done 30m since Red/Blue which released over 20 years ago, i dont see it happening.

I know that, that's why I was modest enough to say 30m.  

I think Pokémon Switch will capture not only Pokémon fans, but also other gamers in general and Nintendo fans who haven't tried it yet due to the limited nature of the game, which will not be a problem anymore since this will be a big HD game. 

Now that they unified their systems into a single one, it will benefit from its fans (handheld gamers) as well as console gamers + new audience, so I believe it will reach the heights of NSMB Wii/DS, MK Wii/DS, Nintendogs, etc.

Actually, stuff like Nintendo Labo might help Pokémon conquering a new audience.

We'll see its potential this E3 already. Reactions are gonna be big on social media. 

Those Pokemon sales are impressive. What bothers me though is that Black 2 did worse than Ultra Moon. I guess we are not getting sequel versions anymore with data like that. Oh well.

Pokemon on Switch should be a big jump. We are going from a 6th generation technology to a 8th generation technology. It will also have 16 GB to play with. So much excitement!