At $99/year — or the recently announced $10.99/month — a subscription to Amazon Prime isn’t cheap, but for people who place regular orders with the e-tail giant, the free expedited shipping may be worth the cost. Now Amazon is offering “No-Rush Shipping Credits” to Prime members willing to temporarily waive their right to what had once been the main selling point of Prime. However, a closer look at the offer raises concerns that many customers may not benefit by being more patient with their purchases.

The shipping credit concept is not inherently bad. After all, if you’re paying an annual fee to get expedited two-day shipping, you should get some sort of compensation when you elect for delivery within five business days. Yet, Amazon’s execution of the concept appears to be more of an attempt to upsell Amazon services than actually provide compensation to patient Prime subscribers.

Amazon’s page describing the offer is vague about how the value of the credits is determined or how long they will last, though it does — by virtue of omission — seem clarify that you won’t be able to put whatever credits you get toward traditional Amazon purchases.

“Depending on the offer you can use your credits to shop for daily essentials on Prime Pantry, Kindle ebooks, Amazon Instant Videos, Digital Music, Amazon Appstore apps, Digital Video Games, Digital Software titles or more,” reads the website.

The actual terms of the offer shed some light on just how disappointed many customers may be.

“Credits are valid for a limited time,” reads one condition, “see detail page at checkout and promotion confirmation e-mail for credit expiration date.”

So you won’t know when your credit expires until after you’ve placed your order and it’s shipped.

“Offer only applies to products sold by or digital content sold by Amazon Digital Services, Inc. (other than limited digital content),” reads another condition, meaning you won’t be able to use any credits for any of the vast number of items sold by third parties — even if they are fulfilled by Amazon.

Since neither the promo page nor the terms explain how the value of credits is calculated, we tried it out for ourselves. Using three different Prime accounts, we filled and unfilled our shopping carts with eligible purchases, ranging from dog food to hammocks to drinking straws to high-end speaker systems.

Regardless of who was placing the order, or the total cost of the purchase, we inevitably were offered a $5.99 Prime Pantry credit, even though none of the three accounts used are active Pantry users.

One cart had items that were coming in two separate shipments, so the “Shipping Credits” reward was two $5.99 Pantry credits. However, that doesn’t mean a $12 discount on any upcoming Pantry order. A look back at those terms explicitly states that “For Prime Pantry credits, a maximum of $5.99 can be redeemed per eligible order.”

That means you’d have to make two Pantry orders in the future in order to enjoy the full benefit of signing away the very reason you might have signed up for Prime in the first place.

If Amazon is going to try to convince Prime members to wait a few extra days for their purchases, it should be more transparent about what subscribers are or aren’t going to get.

Editor's Note: This article originally appeared on Consumerist.