Switch - 906k
https://venturebeat.com/2017/04/13/march-2017-npd-nintendo-sold-906000-switch-systems-last-month/
Oh my, I wonder what that Zelda attach rate is tho?
Edit: Oh my... it's over 100% for Switch... O.o
"The Legend of Zelda: Breath of the Wild game sold over 1.3 million units*. That total includes more than 925,000 units sold for Nintendo Switch and nearly 460,000 units sold for the Wii U console. That means that Nintendo sold more of this game for Nintendo Switch than it sold Nintendo Switch systems, for an attach rate of more than 100 percent. This may be attributed to people who purchased both a limited edition of the game to collect and a second version to play."
Here is a reference for those interested
First month hardware sales in the U.S. according to NPD
Switch is best opening ever for Nintendo pic.twitter.com/k1KnIiGgPd
— Daniel Ahmad (@ZhugeEX) April 14, 2017