SimplyMiles lets you earn American Airlines AAdvantage miles for transactions with a variety of merchants when making the purchase using a Mastercard that’s been linked to the site. They host numerous ‘Mastercard Offers,’ sort of like Amex Offers. But Mastercard doesn’t have the direct consumer relationship that Amex has with its closed loop. So they’re going after American AAdvantage customers.
I earned 7 million miles with their latest promotion. Other readers earned more. And I’ve had several people ask me about the economics of these offers.