The next time you open Facebook to watch a video of cute kids trying British food, or an educational explanation about what happens when you hold your pee, you may have to sit through an ad first.
Starting next year, Facebook will test advertisements at the beginning of some videos. The ads will last six seconds and only show up before videos you seek out in Facebook's Watch section.
That means you won't see these ads in your news feed. You'll only run across a "pre-roll" advertisement when you view something in the dedicated "Watch" section, which Facebook (FB) launched earlier this year. (Facebook says the news feed location doesn't "work well" for these kinds of ads.)
Related: Facebook's new video service is called 'Watch.' But will you?
Watch is Facebook's separate area just for video. It has a dedicated button on the bottom of the mobile app, and a link on the side of the website.
There are some original shows on Watch, like video versions of the popular Humans of New York account. But it's more of a burgeoning YouTube than the next Netflix. The content is mostly short and low budget.
The social network is also tweaking its ads that show up in the middle of a video.
Starting in January, they won't be included in any videos shorter than 3 minutes, and the first ad won't pop up until at least a minute into whatever riveting content you're consuming.
"Viewers tell us they prefer it when the video they are watching 'merits' an Ad Break -- for example, content they are invested in, content they have sought out, or videos from publishers or creators they care about and are coming back to," Facebook said in a blog post.
Related: Discriminatory ads still get through on Facebook, investigation finds
One other new change: Facebook is tweaking its news feed formula, again.
Videos that are part of a series or from creators churning out regular content will now get preferential placement in the news feed.