Twitter has released an interactive map with all kinds of cool data about the location of people who follow NBA teams’ Twitter accounts.
You can see which teams have the most followers by area:
You can see which teams have the second-most followers by area:
You can see where a team’s followers are concentrated:
You can compare how two teams’ followers are concentrated:
You can even zoom into any location to see more specifically any of the above.
Customize the maps, yourselves. Remember, though, this isn’t a scientific study of where fans are located. A team’s Twitter followers are self-selected, and they’re not necessarily fans of that team.