According to Joe Merrick of Serebii.net. Dunno how to imbed Tweets from phone XD And yes, Joe is a trusted source. He won't post things like this unless he's 100% certain of its validity. Congratz, GameFreak!
Serebii Note: Combined between North America, Europe and Japan, Pokémon Sun & Moon has sold at least 7.2 million serebii.net/index2.shtml
Serebii Note: In less than two weeks, Pokémon Sun & Moon have sold 3.7 million units in North America. serebii.net/index2.shtml