Pushing Video On Socials: How View Counter Works

I was just looking to find a current overview for the various ways of uploading, sharing and embedding videos in order to push the view counter. Unfortunately I could not find such a thing, therefore I wanted to create it together with you. Below are the most important Socials including the different scenarios, I started with what I know/think so please feel free to comment or add in:


FACEBOOK

on-platform
Generally video views are being counted after 3 seconds
Autoplay in news feed (muted) counts
Public Counter shows unique views (per account?)

external
Videos can be embedded including autoplay, but views are only counted if user initiated


INSTAGRAM

on-platform
Generally video views are being counted after 3 seconds
Autoplay in news feed (muted) counts
Public Counter shows unique views (per account?)

external
Videos can be embedded, but autoplay is not possible: how are user initiated views counted if they are not logged in?


YOUTUBE

on-platform
Generally video views are being counted after around 30 seconds
Only user initiated views count (autplay only if videos are being promoted)
Public Counter shows total views not uniques

external
Videos can be embedded including autoplay, but views are only counted if user initiated


TWITTER / SNAPCHAT

any ideas?

Just uploaded a 2 Seconds video and it seems like it counts a view when fully watched. In addition the views are actually not uniques but views per account and device. So one account can create multiple views when watching a video from different devices.