The potlatch I learned was enabled by the incredible richness of the environment in the Pacific northwest. The tribes in question lived by a hunter-gatherer economy, which is normally one of barely scraping along most of the time followed by occasional spurts of plenty when some large animal has been killed and there is plenty of food for all. In the Pacific northwest the food practically jumped on the table for you. Hence, it was quite possible to be incredibly rich and this allowed for the conspicuous consumption that was the basis for the potlatch as practiced in that region.