Everything red is personalised information, and there are several variables not used for this donor that could have thanked him for his pledged legacy, extra gifts, specific letters to CCIA and more.
I have also posted the Amex letter - quite cute; handwritten font envelope, stamped and 'from the desk of Pierre Beckert'. I have no idea who Pierre is, and nor does Google, but much more effective in making me feel special* than their regular glossy newsletter / magazine.
And here is the Amex one...
By the way, I know AMEX Platinum is expensive, but with the free travel insurance and free return flight it works out good value... OK, OK, I'm a pretentious mug.