> If you have an executive membership they guarantee that you make back your membership dues.
That's not quite their policy - their explicit policy is "The Reward is not guaranteed to be equal to or greater than the Executive upgrade fee paid." - but they will refund you if you ask for it.
But also remember regular members don't get cash back. The ratio is about 50/50. So about 40 million people pay for membership and don't get cash back.