More than 20 million people have streamed games using Xbox Cloud Gaming, Microsoft CEO Satya Nadella said Tuesday during the company’s first-quarter fiscal 2023 earnings call. That’s double the 10 million figure Microsoft shared earlier this year, just before Epic Games and Microsoft partnered up to bring Fortnite to Xbox Cloud Gaming.

It’s clear that partnership has boosted Xbox Cloud Gaming, particularly because it’s the only game that’s available free via the service and doesn’t require an Xbox Game Pass Ultimate subscription.

While Xbox Cloud Gaming is growing, it’s not clear how other streaming services are fairing in comparison. Google never broke out Stadia numbers before it unceremoniously announced that its game streaming service will end in January 2023. Nvidia doesn’t regularly report GeForce Now subscriber numbers, and we haven’t heard from Amazon about its Luna numbers.

Xbox Cloud Gaming still mostly requires a $14.99 Xbox Game Pass Ultimate subscription, but maybe the Fortnite experiment could see Microsoft open the door to more free-to-play games. Consumers get free access to streaming a game using their phones or through a web browser, and Microsoft benefits from revenue from in-game purchases. It’s a model that you’d expect Microsoft to push beyond just Fortnite in the future.

For now, Microsoft is working on keyboard and mouse support for Xbox Cloud Gaming while bringing the service to Meta Quest VR headsets and working on expanding the titles available to your game library later this year.