I think a that two or three generations ago there may have been some regional "hot spots", perhaps driven by cities with Major League teams. There was still that "I was born in this valley. I live in this valley. I will die in this valley." mentality, hanging on from even earlier. However, these days people go where their career takes them. Internet availability for almost all cards makes it possible from anywhere in the world. I think the collector population is well-dispersed. Just look at the addresses of the people you buy from or sell to..
