Going on sale in Japan on December 3, 2009, Wii title New Super Mario Bros. Wii has sold over 3 million games. In Japan, that's not just fast for a Wii title, it's the fastest.

In its first seven weeks on sale, the game moved 3,002,753 units, making it the fastest title to hit the 3 million mark in Japan, surpassing mega-hit 3-million-selling Wii titles like Wii Sports and Wii Fit.

『New スーパーマリオブラザーズ Wii』が最速で300万本突破 - ファミ通.com [Famitsu]