Who could tell who is playing where.
There are <x> players in your region right now.
There are <x> players elsewhere in the world.
I remember you could check who clan, years ago. And see how many in your clan were online. I think that was removed, though.
I think it's been mentioned that who clan was removed because people would log in, who c, see nobody else, and log off. Which meant someone else might log on 5 minutes later and do the same thing. So on and so on.
psionicist ability? other magickal ability? divination sorcery?
If it were a simple matter of north or south, it might be useful to maybe - five people.
But not everyone is in the north or south. If you're in a remote area, or area mostly unpopulated by PCs, you might see "there are 0 people besides yourself in this region." How is that going to be of any use to you whatsoever? Conversely, if you see there is one, and you're expecting zero, that's going to tip you off OOCly that you're not alone - but ICly there's no reason your character should know that.