“Most literary agents advise young writers to avoid writing short stories. [...] If Edgar Allen Poe were alive today, his agent would constantly slapping him upside the head with tightly rolled copies of his brilliant short stories and novelettes, yelling, "Full-length novels, you moron! Pay attention! What's the matter with you -- are you shooting heroin or something? Write for the market! No more of this middlelength 'Fall of the House of Usher' crap!”

Source: Wikiquote