Dear billionaires, I've wrapped myself in the finest of polyester so that you will take my message seriously. Here at Crash Course we've done a lot of research into our demographics, and our show is watched primarily by grammar Nazis, muggle quidditch players, people who have a test tomorrow, and billionaires. And I have a message for you, billionaires. It will never be enough. Your relentless yearning is going to kill us all. Best wishes, John Green. Speaking of billionaires, the goods that traveled on the Silk Road really only changed the lives of rich people.