American Airlines is partnering with the charity StandUpToCancer and is offering up to 50X miles when you donate from 25-10,000 dollars using your American Airlines Mastercard (either via Barclays or Citi). To commence the donation, you must do so from here. All other sources will get 25X.
100% of your donation goes to cancer, so that’s great! Even if you look at this as buying miles, you come out ahead as a 50,000 miles would cost you only $1000, instead of the standard $2000. You have until either September 30th or when they reach their target goal of $3,000,000 in donations.