The biggest difference between the USA on the one hand and the UK, France and Germany on the other is the size of the domestic market.
In a country with huge distances, sparse population densities (away from the coasts), and a lack of a comprehensive passenger rail network, flying is the transport of necessity, and, until recently, it was dirt cheap! Every tiny "two-bit" town has an airport with (at least) links to the nearest small regional base.
Hubs such as ATL, BOS, CLT, DCA, DFW, DTW, IAD, IAH, LAS, LGA, MDW, MSP and SEA are about 90%+ domestic. Even the large hubs like EWR, JFK, LAX, ORD, SFO, etc., are probably majority domestic. In this respect, the USA is more like Argentina, Australia, Brazil, Canada, China, India and the Russian Federation than like any country in Europe!
Last edited by Fairdealfrank; 21st Jun 2012 at 01:24.