Pokemon: Let's Go, Pikachu! and Pokemon: Let's Go, Eevee! has sold three million copies worldwide in its first week on shelves. 

The news comes straight from The Pokemon Company on Twitter (translated by the good folks at Gematsu), and means Let's Go is already the fifth best-selling Switch title of all time.

It's a notable feat when you consider Let's Go isn't even a mainline Pokemon release, but rather a casual re-imagining of Pokemon Red and Blue that pulls over mechanics from the Pokemon Go mobile game. 

Despite that apparent handicap, the title also managed to sell over 660,000 units in Japan during in first three days on home soil, helping triple Switch hardware sales in the region.