A year ago, the word “fortnight” was relegated to relative obscurity—an archaic way of saying two weeks. In July 2017, however, all that changed. After software developer Epic Games released the blockbuster video game Fortnite Battle Royale—a multi-platform, free-to-play game in which players participate in a cartoonish fight for survival in a post-apocalyptic world—the word “Fortnite” can now be heard everywhere.

Unlike other free games, Fortnite does not include ads; rather, to generate revenue it relies solely on in-game purchases from players to customize their avatar’s appearance (called “skins”) with no other qualitative enhancements. Despite its simple premise and novel business model, Fortnite has been an overwhelming success—boasting 45 million players as of February 2018. USA Today recently reported that in May 2018 alone, Fortnite earned over $318 million, with over $837 million in revenue in the last three months. According to Forbes, the game now earns $1 million a day just on mobile devices.