The creeping commercialization of one of Facebook's most personal spaces continues apace, thanks to the new addition of video ads in Messenger.
The ads will appear in the inbox section, where people see a list of their messages from friends and other contacts. (Sponsored posts with images and other creative elements already appear there.)
The video ads automatically start rolling when a user scrolls over them. This mimics the style of video found across Facebook properties including News Feed and Instagram. The ads are being introduced slowly into Messenger, which has 1.3 billion monthly active users, according to Facebook, while the company monitors consumer reactions.
Facebook, however, won't let people opt-out of receiving the ads, but they can hide them by tapping on a three-dot icon. Facebook says it takes that action into account when deciding what types of ads to show people in the future.
Facebook, which spun off Messenger into its own app in 2014 and introduced the first non-video ads just last year, announced the expansion of its video ads while attending the Cannes Lions International Festival of Creativity in France.
The company typically tip-toes its way into new ad experiences. In 2014, it rolled out autoplay video ads into the main News Feed. Last year, the company altered the autoplay video ad experience by turning on the volume instead of running them without sound by default. That meant if a person's volume was turned up on the phone, the ad would run with sound, too.
This year, Facebook started running pre-roll ads before select videos, like those created by professional media partners inside its new YouTube-like section, Watch. The pre-roll ads were introduced after the company banned the format for years due to concerns that consumers would not like the experience.
Advertisers can buy Messenger video ad placements as an extension of campaigns running on Facebook. They can't set a campaign to run exclusively on Messenger, Facebook says.