When an author promices to sign a very large amount of pre-ordered books in an ever decreasing amount of time.
Symptoms include bad fashion sense, increase puff levels, RSI, and stunted youtube videos. Sypmtoms fade once book is released and signing - the cause - also stops.
2011 John Green's promise to sign all copies of pre-ordered 'TFIOS' (The Fault In Our Stars). Now he has Signing Madness.