Rakuten, formerly known as Ebates, started to allow new members to earn Membership Rewards points in lieu of cash back back in March of this past year. Well now, Rakuten lets all members earn Amex Membership Rewards points instead of cash back.
To switch, you need to go into “Account Settings” and select Membership Rewards points as your payment method. Note, if you have money due to you, you will have to redeem that for cash back and earn points moving forward. Also, my Amex credentials that I needed to enter were not working with Safari, but they did work with Chrome.