[I don't know if Facebook invented this (and if they didn't, I'm sure one of my readers will alert me to who did), but it's certainly the service which has used it to greatest effect which I suppose is the case for anything they put to use given their scale.]

One problem with embedded videos as opposed to text online has always been the high cost of sampling the video. Especially for interviews, I'd almost always rather just have the transcript than be forced to wade through an entire video. Scanning text is more efficient than scanning online video.

Facebook has, for some time now, autoplayed videos in the News Feed with the audio on mute. Not only does it catch your eye, it automatically gives you a motion preview of the video itself (without annoying you with the audio), thus lowering the sampling cost. To play the video, you click on it and it activates the audio. I'm sure the rollout of this UI change increased video clicks in the News Feed quite a bit. Very clever. I've already seen this in many mobile apps and expect it to become a standard for video online.

[It's trickier when videos include pre-roll ads; it's not a great user experience to be enticed to watch a video by an autoplayed clip, then to be dropped into an ad as soon as you act on your interest.]

Someday, the autoplayed samples could be even smarter; perhaps the video uploader could define in and out points for a specific sample, or perhaps the algorithm which selects the sample could be smarter about the best moment to select.

It's not just video where sampling costs should be minimized. Twitter shows a title, image, and excerpts for some links in its Timelines, helping you to preview what you might get for clicking on the link. They show these for some but not all links. I suspect they'd increase clickthroughs on those links quite a bit if they were more consistent in displaying those preview Twitter cards.

Business Insider and Buzzfeed linkbait-style headlines are a text analogue, albeit one with a poor reputation among some. Given the high and increasing competition for user attention at every waking moment, it's not clear that services can leave any such tactical stones unturned.