Originally Posted by
srockgibson
I don't know about AA and UA, but several of us DL Liletime members shared with Delta the original NW LIfetime offering materials. NW used to aggressively sell those LIfetime memberships when you entered the Top Flight Club (later renamed World Club). The option of using the club when flying any airline was a key feature in the sale. I don't know whether that was true with AA or UA.
You used to be able to enter NW clubs even when you were not flying at all. DCA and SFO clubs were pre-security and you could still get to them post-9/11 without having a ticket. I bought a couple 3-year memberships I'm working through (currently on second one) that I purchased prior to changes requiring same-day DL flights. Guess I'm not important enough to get the grandfather treatment.