YouTube is now letting creators with at least 10,000 subscribers live-stream mobile video — and it’s giving them a new way to make money from their most ardent fans.

On Tuesday, YouTube announced the official launch of “Super Chat,” which lets users watching a live stream “get a creator’s attention” by purchasing chat messages highlighted in various colors and stay pinned to the top of the chat window for up to five hours. And the more a user pays, the longer it will stay pinned in the ticker and the long the message can be, according to YouTube.

Super Chat purchases are currently supported on computers and YouTube’s Android app, but not on the iOS version. It’s worth noting that Apple takes a 30% cut of all revenue from in-app purchases.

YouTube hasn’t disclosed how much of the Super Chat revenue it will share with creators. It takes a 55% cut of ad revenue, and says on its support site that creators will “receive Super Chat revenue in the same way that you receive ads revenue with AdSense.” A YouTube rep declined to reveal the split for Super Chat but said “creators keep the vast majority of the revenue.”

For other services, fan purchases of emoji and other “virtual gifts” for their favorite live-streaming creators have been a big revenue generator — the appeal is that individual users can get a real-time shout out from the stars they’ve just gifted.

Amazon’s Twitch game-broadcasting service lets channel subscribers use enhanced emjoi in live chats with video-gamers. And Musical.ly has claimed the top Live.ly creators raked in an average of $46,000 over a two-week period from emoji purchased by fans. Facebook has heavily promoted its live-streaming feature, Facebook Live, but doesn’t currently offer any similar monetization mechanisms.

Super Chat purchases start at $1, but that only highlights a user’s name in blue and doesn’t pin it to the video stream. Messages purchased for $5-$9.99 are highlighted in green with messages up to 150 characters (staying in the ticker for up to 2 minutes), while the max allowed purchase is $500 for a red-highlighted message up to 350 characters that will stay pinned on the live stream for up to 5 hours. Users can purchase Super Chat messages via their Google accounts, which in most countries allow payments from credit and debit cards as well as PayPal.

YouTube said Super Chat is available to creators in more than 20 countries — including the U.S., the U.K., Canada, Australia, Brazil, France, Germany, India, Japan, South Korea, Spain and Mexico — and to viewers in more than 40 countries. It’s available to creators who have at least 1,000 subs.

Live video isn’t new for YouTube — it first launched live-streaming back in 2011 — but it has heretofore let most creators only launch broadcasts from the web. Last year YouTube launched mobile live-streaming for select creators; the Google-owned video giant says it will widen mobile live-streaming to all users in the future.

To begin live streaming from YouTube’s mobile apps, users simply press the “capture” button and they are instantly live. Streamed videos have all the same features as regular YouTube videos, including the ability to be searched for and discovered via recommendations or playlists.

YouTube says it has been working with “hundreds” of creators in the last few months to test and refine the mobile streaming experience. Based on that feedback, it made changes like slowing down live chat and improving streaming quality across devices.