According to a New York Times reporter who spoke to Reggie, Verge reports that The Switch outsold any console launch in Nintendo's history in its first two days. BoTW also outsold any non-pack in game for any Nintendo launch as well. 

Source: http://www.theverge.com/2017/3/6/14836170/nintendo-switch-broke-sales-records-americas-zelda-two-day

However, this is Reggie we are talking about; Reggie through a reporter reported by The Verge. So we shall see how this pans out.

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Japanese Sales: https://prtimes.jp/main/html/rd/p/000003117.000007006.html. First number on this website is the Switch's HW numbers and the second is BoTW's SW numbers. All sales numbers are estimates of Famitsu.

Switch JP Sales: 330k+

All other relevant consoles in Japan (http://gamrconnect.vgchartz.com/post.php?id=8329271) :

PS4: 322k
Wii U: 308k
3DS: 374k
Vita: 324k
Wii: 371k
DS: 468k
PSP: 160k

So Wii sold 600,000 in 8 days. So I'd say less than 400,000 in 2 days?

So if Switch sold more than Wii for the first 2 launch days. Switch sold more than 400,000

Not that impressive. Ps4 1million sold day 1. We all knew Switch was going to sell well right off the gun.

Very impressive. People forget the PS4 launched in late November - prime holiday sales period - while the Switch launched at the start of March.

Very good especially how it got sold out quite quickly.

I want numbers already!

Great news.

Great job Nintendo! This is only positive news! Really enjoying the Switch era so far. I have yet to achieve getting one tho lol. 

If it's better than other Nintendo systems, then that's the impressive metric. Million day one launches for consoles aren't going to be a regular thing. It's doing good in the US for now, in March at that. 

not bad, but if they are really good worldwide I don't see why Nintendo wouldn't be vocal about it

hopefully an announcement is imminent

It is impressive considering this was within a very limited quantity.