In accordance with the mobile analytics firm Sensor Tower, Epic Games’ iOS port of smash hit Fortnite has acquired more than 15 million dollars in its initial three weeks on the market. As per the most recent report of the company, Fortnite on iOS is presently out-earning mobile heavyweights such as Candy Crush Saga, Pokémon Go, and Clash of Clans on a weekly revenue basis, earning 6.4 million dollars in the last seven days in comparison to 5.8 million dollars of Candy Crush Saga. Granted, such games have all been out for years, with the Candy Crush Saga presently a six-year-old mobile game. But each of the game on that list has been at the top of the App Store for many years together, and they have each matured into huge and stable revenue-generators. At least for the present, the Fortnite, is leading the pack.

Unlike most of the mobile games, some of which let the players pay money to advance progress, Fortnite only sells silly costumes, goofy in-game dance type animations, and some other cosmetic items, as well as a three-month 9.99 dollars subscription service known as the Battle Pass. And while these metrics for the Fortnite seem to be eye-popping, they are really not that surprising. The game is a global phenomenon because of a blend of smart timing, the free-to-play model of Epic, and the increasing and innate popularity of the battle royale genre.

The genre was made popular by Playerunknown’s Battlegrounds, from which Epic borrowed the key concept of 100 players parachuting onto a deserted island with the last person standing being the victor. But with the Fortnite, a free game with a much more accessible difficulty curve and much more family-friendly and cartoony visuals, the genre actually took off.

The mobile version of the Fortnite succeeds in part as it is a similar copy of the desktop and the console versions of the game, down to letting the players keep their progress and the cosmetic cache across the platforms. That is the reason why the players are comfortable spending money on the mobile version of the game; all the in-game emotes, skins, and the other cosmetics carry over to PlayStation, PC, and Xbox. PUBG even exists on Android and iOS in an astonishingly stable state- it is designed by the Chinese gaming and the technology giant Tencent — but the progress does not carry over to the other platforms.

In accordance with the Sensor Tower, earlier in the current week, when Epic lifted the invite-only hurdle for the Fortnite on iOS, a mechanism that the developer had kept in place since the launch of the game on 15th March, the company witnessed the daily mobile revenue triple from around 600,000 dollars to 1.8 million dollars.

The Sensor Tower estimates the Fortnite has been downloaded about 11 million times on mobile alone. In accordance with Superdata Research, another game analytics company, Epic raised around 126 million dollars through Fortnite in-app purchases in the month of February. The mobile sales surely would boost that figure in the months to come.