I donated online to my alma mater last month, and also grabbed a few gift cards throughout the year in order to take advantage of certain AMEX offers, and they all definitely counted. My personal experience has been that the only thing included in the "purchases" amount on my statement, but EXcluded from both earning miles AND minimum spend for MQM boost (but strangely INcluded in spending for MQD waiver) is Serve loads. I think a good rule of thumb in general would be to consider whether AMEX would typically get a swipe fee from the purchase. They would for a gc from a grocery store, restaurant, or other merchant, but not for a Serve load.