In all, NPD says that 1.5 million Switch consoles were sold during the five weeks that make up the December reporting period.
Various Switch titles also finished high on the chart of most sold.
In total, Switch, 3DS and SNES Mini sales accounted for over half of all game hardware units moved last month in the USA, with over 2.6 million units sold during the lucrative holiday season.
Perhaps more impressive (or, at least more surprising) than the Switch sales, was the continued success of the humble 3DS. Nintendo has a Pikachu-themed New Nintendo 2DS XL coming stateside later this month.
All current versions of the 3DS (including 2DS) moved over 750,000 units altogether, which made it the best December for the line in four years since 2014.
Combined hardware sales of Nintendo Switch, Nintendo 3DS and the Super Nintendo Entertainment System: Super NES Classic Edition system topped 2.6 million units, which accounted for more than half of all hardware sold during the month. Super Mario Odyssey and Mario Kart 8 Deluxe were #3 and #4, The Legend of Zelda: Breath of the Wild at #9, Pokémon Ultra Sun/Ultra Moon at #13/#14 and Splatoon 2 at #16. Though we can likely expect the Switch to remain popular for some time to come, we're entering a period that has traditionally been slow for the games industry, so its momentum could certainly slow down.