Two weeks ago on a Friday afternoon from ATL to DFW I decided to standby on an earlier flight instead of the one I had an upgrade on. The gate area was a zoo and all the flights appeared overbooked in coach and full in F. Nevertheless, I was the first one called from the standby list and I happily took my coach seat. After boarding was completed, the GA came in and asked me if I wanted to be upgraded. Well, let me think about it... This has happened to me only once in a blue moon but I'm glad to be an EXP on AA knowing that they do look out for you.