People are ??? ??? ?? ??spending a lotof money in the YouTube app.

The Google-owned platform has taken in more than $563 million in 2019, bringing the app's lifetime revenue to more than $1 billion, according to new analysis from app analytics firm Sensor Tower.

That milestone places YouTube amongst an elite group of just a handful of non-gaming apps to hit the $1 billion mark. Sensor Tower only looked at revenue from in-app purchases and subscriptions, so the $1 billion doesn't reflect YouTube's ad revenue, or what the company has made from the YouTube Music or YouTube TV apps.

YouTube has consistently ranked as one of the most-downloaded apps, so it's not necessarily surprising that it's also a major moneymaker for the company. Google has been notoriously secretive about YouTube revenue, but Sensor Tower's report highlights just how much in-app spending has spiked in the last year.

YouTube users spent more than $563 million in the app in 2019 so far, compared with $277 million in 2018, according to Sensor Tower. And spending outsides of the United States has been growing even more quickly, jumping from $53.8 million in 2018 to $181.7 million in 2019.

A big part of that is likely due to YouTube's expansion of its monetization features for channel owners, like SuperChat, or the ability to sell products.

"Today, thousands of channels have more than doubled their YouTube revenue by using new features that help fans engage with creators, like Super Chat, Channel Memberships, and Merchandise," YouTube CEO Susan Wojcicki wrote last month."More than 100,000 channels have received Super Chat, and some streams are earning more than $400 per minute as fans reach out."

YouTube didn't immediately respond to a request for comment, but Sensor Tower's analysis indicates these efforts are starting to pay off — literally.