Thanks to a targeted promotion from American Express and Amazon, you can save on Amazon purchases by redeeming just one Amex Membership Rewards point.

There are usually several versions of this offer, so click here to see which one your account qualifies for. The discounts can range from 15%, 30%, 40%, and even up to 50% off, though there’s always a maximum savings cap.

For example, I was eligible for 15% off, with a maximum savings of $15, when using Membership Rewards points as part of my payment.

Here’s how to take advantage of the offer:

1. Activate the offer.
2. Select the product you’d like to purchase.
3. At checkout, be sure to click the “Use American Express Membership Rewards points” option and apply at least 1 point toward your payment.

Once applied, you’ll see the discount reflected in your total. For my purchase, I was able to save $15 on my last Amazon order.