Last week, I decided to make my second Amazon Kindle Fire purchase, this time as a Christmas gift for someone special (anyone who knows me can start guessing if it’s for you!). The new tablet is so impressive that I didn’t hesitate in putting down another $199… and then all of a sudden, Amazon made it an even easier decision.

While reviewing my order in the very simple Amazon.com checkout process, I was prompted to link my American Express Membership Rewards account with Amazon’s “Shop With Points” program and use points to pay for my new Kindle Fire. After confirming my card’s four-digit CID and agreeing to some terms and conditions, I was done. Easy, straight-forward, and $199 back in my pocket.

Intrigued by how quickly my order was completed, the next day I was surprised to discover that American Express’ Membership Rewards program had been working with Amazon for more than a year. The exchange ratio remains a paltry 1,000 AmEx membership points for every $7 spent at Amazon.com. There are sure to be people who will say I’m crazy for accepting those terms, but I consider membership rewards points “found money.” I’ve donated to charities and upgraded travel accommodations using points without thinking twice.

Here’s Amazon’s example of what customers see when confirming their payment and order, including available American Express Rewards Points, their equivalent value on Amazon.com, and the ability to change the amount of points used or to not apply any points for the purchase.

Online retailers should consider testing something like this or other alternative payment methods like Bill Me Later. You could see an immediate lift in your conversion rate, like Amazon did with me!