The prevailing theory in the 80's was that you could put a hub airport anywhere because passengers would just be connecting from one flight to another. Hence, CO decided to put CO Lite's hub at GSO (a very low cost airport). Of course, the CO Lite experiment proved that you must have some semblance of a local passenger base to operate a hub effectively. A smaller city like GSO just couldn't support a hub operation.

That being said, Piedmont Airlines had a knack for choosing underserved cities like BWI (pre-WN invasion) and DAY for hubs. It would be interesting to see what their route structure would look like today if they hadn't been taken over by US Airways.