Scott Alexander buys the Codex Seraphinianus, a long-desired luxury item, and inadvertently turns his post into an Amazon advertisement.
Longer summary
Scott Alexander describes purchasing the Codex Seraphinianus, a book he's wanted since he was nineteen, as a reward for doing well at his job. He explains that the Codex is difficult to describe and must be seen to be understood, providing links to view it online. Scott was prepared to pay $500 but found a new version for only $80 on Amazon. He then humorously notes that he unintentionally advertised the book and decided to sign up for Amazon Affiliates, turning his accidental promotion into an actual advertisement.
Shorter summary