Stephen Colbert is angry. And when Stephen Colbert gets angry, he also gets really funny and it's very entertaining for the rest of us. So it's a good thing Amazon is pissing Colbert off. You see, Colbert's books are published by Grand Central Publishing, an imprint of Hachette, the publishing company currently struggling with Amazon over the pricing of some ebooks. The pre-ordering and shipping of many Hachette titles has been delayed by Amazon in an attempt to pressure the publisher.

Because Amazon controls so much of the book marketplace, authors and other people concerned about the fate of publishing have complained that Amazon can "bully" (to use John Green's words) publishers into setting prices as low as Amazon wants them. This of course would be really, really bad for the dozen or so people in America who still read books. 

Sources: The Colbert Report