Happy Prime Day 2019! Over the next few days, many people will probably be shopping on Amazon. And all of those purchases on Amazon means they are shipped in Amazon boxes. CNBC takes a look at the business of Amazon shipping boxes. Cardboard boxes are a really big deal in the U.S. Amazon alone shipped over 5 billion packages through Prime in 2017. But as Amazon moves to plastic mailers and paper mailers the corrugated box market is bracing for the fallout. Enjoy below!