Based on publicity information released by Gollancz, the Witcher books by Andrzej Sapkowski have now passed 15 million worldwide sales.
The previous available figure indicated that the series had sold around 6 million copies by the middle of last decade. The massive jump in sales in just a few years is down to two factors: the immense success of the Witcher video game trilogy by CD Projekt Red (the last of which has now sold around 30 million copies by itself) and the success of the Netflix television series based on the books, which debuted last December. As we saw with Game of Thrones on HBO, a successful and well-received TV adaptation can massively drive sales of the books; the Song of Ice and Fire novels sold 9 million copies in 2012 alone and have sold around 80 million extra copies since the TV show debuted in 2011. Whether The Witcher can match those kind of sales remains to be seen.
The first Witcher book - also called The Witcher - was published in 1990 and was a collection of short stories. It was later revised and reissued in 1993 as The Last Wish. A second story collection, Sword of Destiny, was released in 1992. The five-volume "proper" novel series followed: Blood of Elves (1994), Time of Contempt (1995), Baptism of Fire (1996), The Tower of the Swallow (1997) and The Lady of the Lake (1999). A stand-alone prequel, Season of Storms, followed in 2013.