The Fault in Our Stars was #1 on the Amazon bestseller list months before it was even scheduled for release. This caused Penguin to push the publishing date up by 5 months, which doesn't happen very often.
John Green promised to sign every single copy of the first publishing of The Fault in Our Stars. That was 150,000 books, and about 5,000 signatures per day. He did it.
John winning the single most prestigious young-adult book award with his first book.