Since I travel on business for the government, I must use the contract carrier which varies by routing. So I rarely have much choice as to the carrier (though the system can be tweaked, e.g. by flying into JFK instead of EWR). But even when I was in the private sector, I generally took the fastest most direct routing which varied depending on destination.

Over 18+ years, the result is that I have significant balances in many programs but generally have status in only one (which again varies depending on my travel habits). One benefit is that I can usually find desired award seats on some carrier (though rarely if ever on CO).

My experience notwithstanding, if you are in a hub city and your job permits, I think it would be wise to fly as many miles as you can on the dominant carrier so that you get all the status perks. But you should definitely create a new account whenever you travel on another airline as you never know when your patterns will change and you can usually postpone mileage expiration with little effort.

[This message has been edited by Boraxo (edited 11-05-2003).]