Amazing sales all around!
Mario Kart looks set to cross the 30m lifetime mark after this quarter. Breath of the Wild should cross 20m, even if the sequel will be here by late 2020. Smash, Pokémon, Mario will cross the 20m mark as well.
This reminds me of the Wii and DS days when Nintendo's titles sold insane numbers for years and years. And Switch hardware will easily pass 100m units lifetime.
What these numbers show is that it was definitely the right decision to merge the home console and handheld divisions for Nintendo. They can put so much more resources into just one console and each of their titles gets full attention by the market - compare that to the Wii U / 3DS days when most major franchises would get a game on both devices.
One more thing: I really hope Nintendo gets the message consumers are sending when it comes to Zelda games. Zelda is a game about open worlds (Links Awakening was as open as a game could get on the Gameboy) and not puzzles. But world-building is hard and the biggest danger I personally see for them is becoming lazy with the franchise again and "forgetting" to put enough energy into world-building. Twilight Princess's world was partly modelled after Ocarina of Time. Skyward Sword did not have an open world at all. They've been reusing A Link to the Past's world on the 3DS. They've remade Link's Awakening. And they are going to recycle Hyrule in Breath of the Wild 2. They are lazy world-builders, with Breath of the Wild being the glory exception. Zelda as a franchise is incredibly popular right now, but that can change. So I hope they get the message.