Last fall Facebook admitted that its metrics for video view counts were inaccurate, and had been inaccurate for 2 years. It was a nasty bit of news for anyone who had been producing video content for a Facebook page.
It’s been six months. Yesterday, Facebook started rolling out new metrics that will appear in the Insights tab for Facebook brand pages. This article is a good introduction to the changes you’ll be seeing.
Improvements to Video Metrics in Page Insights | Facebook Media.