Facebook is rolling out autoplaying video ads on Messenger, the company confirmed to Quartz June 19.

The ads, which will automatically start playing as you scroll through your messages, start rolling out Monday to a small group of users, a spokesperson told Quartz. The company recognizes Messenger is a different environment than Facebook’s other products like the News Feed on Facebook’s main app, or Instagram, where ads have become a mainstay and may feel less intrusive. “We will be rolling out video ads gradually and thoughtfully,” Facebook said in a statement provided to Quartz. “People that use Messenger each month are our top priority and they will remain in control of their experience.”

But remaining “in control” does not mean you’ll be able to opt out of Messenger ads altogether—it just means you can hide a given ad, report it, or manage your targeting preferences, like on any other Facebook app.

Some users have started seeing ads in Messenger last year. Stefanos Loukakos, the head of Messenger’s ad business, told Recode—which first reported the new video ads—that the ads have not changed user behavior. Here’s his full quote, because it’s… quite something:

“Top priority for us is user experience,” he said from a beachside cabana at the Cannes Lions advertising festival on Tuesday. “So we don’t know yet [if these will work]. However, signs until now, when we tested basic ads, didn’t show any changes with how people used the platform or how many messages they send.” “Video might be a bit different, but we don’t believe so.”

When asked by Quartz about what feedback Facebook has gotten from users on Messenger ads, the spokesperson declined to provide any insight the company had on how users felt about their experience.