May 2018 is the 15th month that the Nintendo Switch has been available for. During the latest month the Wii has grown its lead over the Switch. The Wii outsold the Switch by 800,622 units in the last month and by 3.20 million units in the last 12 months. The Wii is currently ahead of the Switch by 3.65 million units.
The Wii launched in November 2006, while the Nintendo Switch launched in March 2017. The Switch has sold 17.33 million units, while the Wii sold 20.98 million units during the same timeframe.