 As of April 2019, the book series has sold 90million copies worldwide.During the 1980s and early 1990s, Martin's novels had slowly earned him a reputation in science fiction circles, although he said to only have received a few fans' letters a year in the pre-internet days.The publication of "A Game of Thrones" caused Martin's following to grow, with fan sites springing up and a Trekkie-like society of followers evolving that meet regularly.