About two or three weeks ago the Facebook Video app appeared on my Samsung TV. It's an app I can't delete and it loads along with a few others when I turn on the TV. Obviously a biz deal FB made with Samsung.
I watched a few videos. Ads appeared about 20 to 30 seconds into the video. I can close the ad the usual way, same as YT.
Those apps that mysteriously appear are a real pain: Smart TV's are just too smart, imho. Built for marketers to push more "stuff".
I was watching a video online the other day and there were several ads breaking up the video: It was a real annoyance. I could live with pre-roll ads, and those much shorter ads are better from a user point of view as i tend to watch the whole thing, rather than getting part of the story and then clicking skip as soon as possible.
It does seem to be a turnaround of views by Zuckerberg who'd said only earlier this year he'd not go down this route.