A lot of time is spent by companies doing research into the areas they are trying to selling in. There are some companies even dedicated to doing this market research for various other businesses. Companies sometimes need a specific demographic in an area before launching a product or store into an area.
The famous saying, 'he could sell ice makers to the Eskimos' is a simple example of this type of marketing thinking. Eskimos generally live in cold regions so it's silly to think of them buying ice makers. It becomes necessary to see if the type of product you are selling is wanted or needed in a certain area.