(N)የአየር ጉዞ ኢንዱስትሪ ውስጥ የደንበኞች የታመነ እምነት ላይ የሚያደርጉ አካላት ላይ የተደረገ ጥናት/የአየር ጉዞ ኩባንያ ወደ ደንበኞች የታመነ እምነት የሚያደርጉ ጥናት
have a chance to upgrade
not always have a trip
obtain free tickets
enjoy discount
not much different from the one who hasn't joined
not many benefits
low discount percentage
obtain free tickets
have gifts
have a chance to upgrade