Good question Michael. Last year I gave my father (68 yrs old) and his wife Envoy class tickets to Madrid on US Air. I don't think he had ever flown in anything but coach before - certainly not internationally. Most miles for me are banked for premium class international tickets and for my girlfriend to accompnay me on biz travel to decent destinations. Rarely used for domestic travel for myself. Have given some domestic tix to friends and family though.
Gatorboy