Since this has become such a hot topic, I thought it was time to try and centralize the discussion. One thread on how people went about getting added as AUs, then how they got their own AmExes backdated, should help everybody. Some people like Dr. Tang, and my graduate are coy, and don't want to draw attention to themselves, I understand. But those who are willing to share their experiences, please STRUT away.
****Note: As of March 2015, Amex no longer backdates any accounts, regardless of MSD. Any backdated accounts already reporting are grandfathered in.