9 crazy facts about Amazon's holiday sales this year

Amazon had another big holiday shopping season.

According to an announcement the company posted Monday, more than 3 million people joined Prime, the subscription service that offers free two-day shipping, access to streaming movies and music, and other perks for $99 per year, in the third week of December.

Each year, Amazon also publishes some crazy facts about its holiday sales.

Here are the best ones:

1. The most popular request for Alexa, the digital assistant in Amazon's Echo WiFi speaker, was "play music". The most popular songs were "White Christmas", "Sleigh Ride", and "Winter Wonderland".
2. Alexa set 4 million timers during the holidays.
3. Customers read enough books in Amazon FreeTime, the digital subscription service for children's books, to "reach Mt. Everest's peak more than 10 times if put in a straight line in their physical form."
4. Customers spent enough hours reading "The Martian" on Kindle (the novel this year's movie was based on) to add up to 1,000 trips to Mars.
5. Amazon sold enough Rope King Twine to create a string from Seattle to Los Angeles.
6. Amazon sold enough Command Hooks "to hang a stocking for every person in Orlando, Florida."
7. Amazon sold enough Jenga games "to reach the top of the Empire State Building more than 70 times."
8. Amazon sold enough "Jurassic World" DVDs "to equal the height of more than 2,700 Tyrannosaurus Rex."
9. On Cyber Monday, Amazon sold one Adele CD every three seconds.

Disclosure: Jeff Bezos is an investor in Business Insider through hispersonal investment company Bezos Expeditions.