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Previously, the company has revealed how many video views it gets a day. In April, it had 4 billion daily views. In October, it had 8 billion daily views.
Critics pointed out that a "view" didn't really mean much because Facebook counted one any time an autoplay video played for three seconds.
But today, Facebook announced that people watch 100 million hours of video a day.
That's a significant metric change.
Video platform incumbent YouTube started measuring its success in terms of hours watched instead of video views way back in 2012, with the rationale that watch time demonstrated engagement much better than views.
Seeing Facebook change its metric to something closer to what YouTube cares about shows its ambitions to rival Google-owned YouTube as a central hub for people to watch digital videos (and to reap the lucrative advertising dollars that come with it).
So, how does 100 million hours stack up to YouTube?
The New York Times reported in December 2014 that people watched more than 300 million hours of videos on YouTube every day. Then, a person familiar with YouTube's numbers told Business Insider that watch time had swelled past 500 million hours a day in July. YouTube has also said that its watchtime has been growing 60% year-over-year.
With some rough math, let's say then that YouTube now has around 650 million hours of watchtime a day.
Facebook video could be seeing about one-sixth of the watchtime as YouTube.
Because YouTube hasn't actually released an updated stat in a while, we still don't have a perfect idea of how YouTube and Facebook's platforms compare in terms of watchtime.
And they still have very different kinds of content (Facebook favors much shorter-form videos than YouTube, and is struggling with rampant copyright issues). But, we're a whole lot better informed than we were before.
