if a post was created in one territory but then becomes popular in another territory - how will that work?
What do you mean? You mean how ranking on home (the mother of all front pages) then will work?

As a random example lets say there is a territory ~vikings where people share their interest in the vikings (😅). Then lets say there is a territory ~history. If someone writes something amazing in ~vikings - could there be a way that it might be surfaced on the ~history territory without the poster specifically cross-posting it there?
For me the reason this would be really cool is it gives the more niche territories a chance of being discovered on the more broad territories.
K00b mention an update to the territories that brings sub subs So it will be ~history/vikings
I still think this is a good question. There is a lot of content that might be valued on multiple subs, but the original post didn't cross post it. It would be nice if we could pay the posting fee to cross post something from one territory into another and then get some share of the zaps that come from that territory.
aah thanks I missed that 👍

from the announcement:
create territories within other territories, eg ~bitcoin/privacy and ~bitcoin/mining the territory founder can sell sub-territories to other stackers at a price of their choosing