Interesting post from a Illinois discussion board. Don't know if it's true, but fun to believe it is:
From the Illinois board....
I've been with AmEx for 25 years, and they are my financial planners. I recently called my planner and the AmEx corporate Office to express my extreme displeasure with their support for the Duke University Basketball program - telling them I would seriously consider both cancelling my card and moving my assets to another company.
I got a call back from someone fairly senior saying the entire ad campaign had been much more controversial and counterproductive than they imagined. I was told they have seen card cancellations up almost 15% since the ads started running.
Express your dissatisfaction with AmEx - it will have an impact - even if you dont' have a card, let them know you don't appreciate their ads and it will affect your decisions in the future.