It sounded like a really nice holiday extra: you could tip your hard-working Amazon delivery driver by simply using your Alexa device (or the app on your phone) to thank your driver, and they would get a $5 tip from the company.

The program started on December 7th and was probably meant to publicize Amazon’s new feature that allowed users to thank their drivers through their Alexa apps. Available to all US delivery drivers delivering on behalf of Amazon, it didn’t last long. Amazon only offered the virtual tips in response to the first one million thank you’s — and that $5 million was apparently used up within a couple of days.

According to Lauren Samaha, Amazon spokesperson, “More than 1 million ‘thank yous’ were shared and while the promotion period has ended, drivers will continue to be notified of the gratitude received.” Whether the drivers really appreciate the thanks will depend, I guess, on the individual’s feelings about their job. But hey! It can’t hurt.

It’s simple to do: after you’ve received an Amazon package, say “Alexa, thank my driver” to your Echo or other Alexa device (or to your phone if you have an Alexa app), and it will extend your thanks to your driver. You’ll also get an acknowledgment that reads: “From Alexa: Thank you for your appreciation! We’ll share your thanks with the driver.”

If you want to leave a more substantial thank you, it might be a nice idea, when you’re making your order, to request your driver ring your doorbell when the package is delivered — and be ready to hand them a $5 bill when they show up. It may not be as cool as sending a tip via an app, but it may be more certain — considering that Attorney General Karl A. Racine of Washington, DC, has initiated a lawsuit against Amazon for stealing tips from delivery drivers through its Amazon Flex service.