Most of my publishing career was in sales but I spent about a year as an editor at Penguin USA. I learned many things during that time, of which the oddest was the snobbish rivalry between editors of literary fiction and popular fiction, also sometimes manifested as hardcover books vs. paperback books. The latter sometimes occurred on the sales side too but
that is another story. Or three.
One day I heard the editorial assistants had been told to spend a Friday afternoon dealing with fan mail. They were bribed with pizza and soda to do this about twice a year. I offered to help which surprised them (hierarchy) but won me a few friends.
Several huge boxes of mail appeared and were dumped onto a conference room table. We each took a handful and started to go through it. It was completely amazing the way people addressed/sent letters and, based on how they were addressed, even more surprising they actually reached us at Hudson Street.
