This thread has me thinking...

At some point, the value of the customers given lifetime gold will deteriorate. For example, with the AAdvantage program 20 years old, 1MM means an average of at least 50K miles per year. When the program is 40 years old, a longtime member might hit 1MM with only 25K per year.

So suppose AA does need to change this someday. How could they do it most fairly? What change would be the least painful?
- Raising the threshhold to 1.5MM or 2 MM ?
- Counting only flight miles going forward?
- Requiring X number of years of Gold (implying flight miles)?