I think you're thinking of Nation RP's, because I've never seen that happen in Columbia. Faction trading in Columbia tended to be small-time and more realistic. Boxes of ammo from the Pitt, slaves from Paradise Falls, food from Point Lookout etc. And Columbia tended to be heavily centered around characters and their stories as well.
Honestly what I like about them is precisely that: they aren't dependent on a GM to move things along. Its much more free-form. With a "make it as you go story." Which isn't held up by inaction on the GM's part. Of course that lack of moderation can be problematic sometimes, which is a downside. But overall most players in Columbia did well keeping themselves in check.
I'd encourage people to read a thread or two of Columbia (the last one especially). Because, honestly, I thought what we did there was some of the best writing I've seen on this board. With character arcs that came to definite conclusions, and factions arcs which did the same. All the while maintaing a sense of something greater, as if the region was actually alive with activity.
But anyway, is there a possible ETA on a sign-up thread for this character RP?