Usually it’s a post with something about wildlife in a particular location. Then they request that you “please post where you’re from so I can track how far the video” went. This makes no sense, geographic location makes no difference to Facebook or the internet.
Since it makes no logical sense, I suspect a scam of some sort, but I can’t make out what it would be. Or are people just that stupid? (both the poster and the responders)
The poster just wants to know how far his video has reached. Is someone watching his video across the state, the country, the continent… the world? Uploader is just curious even if it seems a bit juvenille or attention seeking. It makes no difference to the internet or Facebook, as you mention, but may make a difference to the uploader to see how far his/her video has spread.
If you see a lot of them that just means your Facebook network has a lot of people who like and comment on these.
I hardly see any, maybe once a month I see a “I’m teaching my 5th graders about internet safety. Help me show how fast and wide a picture can spread.” It’s possible there’s some scam down there, but I think they are authentic.