What about being able to send messages to all nobles in adjacent regions?
The example that comes to mind is that if you want to have a RP exchange with a group of people of another realm, the only way to be certain it happens is to stay for multiple days in the same region. It is very difficult to travel together, because one missed turn means you travel out of phase. If you could communicate, you could travel together, at the cost of eventually skipping a turn for the stragglers.
