The rapid appearance of competition changed the nature of the program .
As airlines began to compete on the features of their frequent flyer programs , AAdvantage liberalized its rules , established partnerships with hotel and rental car agencies , and offered promotions such as extra free beverages .
The rapid appearance of competition changed the nature of the program , and as airlines began to compete on the features of their frequent flyer programs , AAdvantage liberalized its rules , established partnerships with hotel and rental car agencies , and offered promotions such as extra free beverages .