You might not have heard of Twitch, but it’s one of the most popular places on the internet. Millions of people every day use the app to do everything from watch their favorite live streams to play videogames to solve math problems in real time.

Video games are still the biggest category of live streams people tune into on Twitch, and the biggest games — like Grand Theft Auto and Fortnite — still dominate time spent on the platform. Recently however, there’s been a new addition to the top 10: gambling. It’s now the seventh most-popular content category on Twitch. And it’s not just any gambling.