I'm wondering how widespread this phenomenon is: retail and restaurant chains that will not expand outside of a certain area, not because of financial or logistical constraints, but because they feel a sense of loyalty to a certain region.
Two examples come to mind:
Blake's Lotaburger: a fast food chain in New Mexico. It's quite popular in the state, but not one location is outside of New Mexico. Supposedly several years ago, when asked why the chain never opened a location outside of the state, the owner said "There's just some things that belong only to us."
Honey Hut: a very popular locally owned chain of ice cream stands, all of which are located on the West Side and the western suburbs of Cleveland. The owner reportedly takes the local East Side-West Side rivalry to heart, and refuses to open a Honey Hut east of the Cuyahoga.