Retail giant Amazon announced Wednesday that it would bring back its delivery-driver tip program after a successful response from the first round.

The program is called "Alexa, thank my driver" and it allows Amazon customers with an Alexa account to tip their driver $5 at no cost to them. It is offered to the first 1 million "thanks yous" after a package is delivered.

The program was introduced on Dec. 7. and lasted for only one day due to the high response.

"In response to the incredible impact of the celebratory promotion, in which we reached 1 million "thank yous" within 36 hours of launch, we are spreading even more joy, Amazon said in an update of the original news release.

"Starting December 21, eligible drivers will be offered $5 per 'thank you' for another 1 million 'thank yous.'" Amazon said.

The "Alexa, thank my driver" program will also award the top five drivers who receive the most "thank-you's" $10,000 and an additional $10,000 to their charity of choice, according to the press release.

The return of the program comes during a peak season for Amazon due to many people using the platform to order Christmas gifts, especially last-second Christmas gifts. This leads to extra work for the delivery drivers.

This Amazon peak season lasts through Christmas into early January.

Amazon Alexa