Epic Games’ iOS port of smash hit Fortnite has earned more than $15 million in its first three weeks on the market, says mobile analytics firm Sensor Tower.

According to the company’s most recent report, Fortnite on iOS is now out-earning mobile heavyweights like Candy Crush Saga, Clash of Clans, and Pokémon Go on a weekly revenue basis, earning $6.4 million in the last seven days compared to Candy Crush Saga’s $5.8 million.

Unlike those other games, however, Fortnite sells only silly costumes and goofy in-game dance animations, among other cosmetic items and a three-month $9.99 subscription service called the Battle Pass.

Sure, that’s a pretty eye-popping series of metrics for Fortnite, but it’s not that surprising.

The game is a worldwide phenomenon due to a blend of smart timing, Epic’s free-to-play model, and the growing and innate popularity of the battle royale genre.

The genre was popularized by Playerunknown’s Battlegrounds, from which Epic borrowed the core concept of 100 players parachuting onto a deserted island, with the last person standing being the victor.

The text above is a summary, you can read full article here.