Came across this sweet deal today when I was looking for a decent promo code for a Blinkist sub - saved me $180
It says you must be a "US" American Express Card Member to redeem but I just tried it with my NZ AMEX login details and It worked just fine.
Just remember to 'turn-OFF auto renew' once you have set-up your Blinkist account.
If you don't know about Blinkist:
Blinkist brings you knowledge from top nonfiction and podcasts, so you can learn anytime, anywhere. Read or listen to the key ideas from bestselling nonfiction titles in 15 minutes.