Originally Posted by
gemac
Why would AA want to trick someone into using their miles? AA will have to pay for the subscription. If you use your miles on an AA flight, it will be on a seat that AA's yield management figured would be empty anyway. The best scenario for AA, of course, is for you not to use them at all. I think the letter is a way to provide value to customers who are not redeeming their miles for tickets.
I am pretty sure that in the big-picture, it is beneficial for AA if you use your miles for magazine subscriptions, points.com, etc. over actually using them to get on one of their aircraft.