Super Mario Odyssey had a hell of a launch. With over 2 million sold in the first 3 days, Super Mario Odyssey is, by far, the fasting selling Mario 3D worldwide.
We have not data for every countries, but we know Mario Odyssey sold over 500k in Japan according to Famitsu withouth digital sales, when every others 3D Mario failed to sell 400k at retail, and we know UK launch was another record launch.
Now, i personally expected a launch like that... even so, this makes me thinking, we talk about a game which is gonna have HUGE legs this holiday season, expecially thanks the bundle, and in general, we talk about Mario. Mario always has legs, expecially if we talk about a successfull console, which is the case of Switch.
This is what the others Mario 3D games have sold (shipped) since 1996:
[N64] Super Mario 64 – 11.91 milioni
[NGC] Super Mario Sunshine – 5.91 milioni
[WII] Super Mario Galaxy – 12.72 milioni
[WII] Super Mario Galaxy 2 – 7.41 milioni
[NDS] Super Mario 64 DS - 11.06 milioni
[3DS] Super Mario 3DLand – 11.40 milioni (In crescita)
[WIU] Super Mario 3DWorld – 5.70 milioni (In crescita)
To be honest, i predicted 15 million units for Super Mario Odyssey in January 2017... but right now, i don't know, i think this number may too low. The fact is that, so far, we saw a lot of absurd records for Switch games, just look at Zelda: Botw, this game right now is gonna sell easy over 10 million, could end with over 12 million as well, and before that, the record for a Zelda game was just 8.5 million (Twilight Princess).
Splatoon too, will easy surpass 10-12 million, as for the first quarter we already saw 3.61 million, and the original only sold 5 million.
The fact is that, Nintendo IP right now looks stronger than ever, and i think Mario 3D, with all this Nintendo success, and good word of mouch, can break insane record too.
So what do you think? Will Mario Odyssey sell 20 million lifetime?