Some FB Videos on YouTube only?


I came across my first FB video by accident by searching for workout videos on YouTube. The video was "32 Minute Home Cardio Workout with No Equipment - Calorie Blasting Cardio Training". Here's the link

It is still one of my favorites.

I eventually found the actual FB site, and find the site's video search/filter capability very helpful.

I've noticed, however, that some videos do not show up on the actual FB web site (e.g. like the one mentioned above), but are only on YouTube. Has anyone else noticed this, or am I just not looking close enough? If certain videos are just on YouTube, can someone explain why? It would be nice if all the videos were accessible through the official FB site so you could search for them and mark them as favorites.