Amazon brought back its Thank My Driver holiday promotion this year and it has already reached its maximum amount.The promotion allows thankful customers to tip their most recent delivery driver $5 at no cost to the customer by stating Alexa, thank my driver from an Amazon Alexa device or by selecting it in the Amazon app.The promotion started on Dec. 4 and reached the cap of two million driver tips in just six days.RELATED STORY | Has tipping fatigue changed how Americans should tip for the holidays?But you can still show your Amazon delivery driver appreciation and help them earn some extra cash for the holiday season.For the rest of December, Amazon will be awarding its top-thanked drivers with $100 every day and the top seven thanked drivers from each week $10,000.At the end of the month, the top seven thanked drivers from the entire promotion period will receive $25,000 and can choose an additional $25,000 to go to their charity of choice, all paid for by Amazon.RELATED STORY | Amazon faces global pushback from its workers in annual 'Make Amazon Pay' strike