Bandai Namco has announced that Tekken 7 has sold over four million units worldwide (PS4, Xbox One, PC).
The game released on June 2, 2017, and since that time it has been supported both paid and free DLC containing characters, moves/mechanics, and costumes.
Last fall the game hit the three million mark, and the fact that it has added on another million in less than a year from that is certainly a good sign.
[Source: Bandai Namco]
Source: Game Informer