What is "fan letter"

Usage examples of "fan letter".

I found he had printed a fan letter of mine in the issue about to be published, and another in the next-so he knew the genuineness of my interest.

We got a dialogue going many years later, because I sent him a fan letter after reading Omnivore.

The other men found themselves staring at Desmond's fan letter as if it were a corpse at a wake, silence surrounding them, trying to guess where the killer might've gone.

Kathleen's response to the first gushing fan letter had been courteous but cool.

She rooted past untidy bundles of canceled checks, dead C, D, and 9-volt batteries (for some reason she had never been able to shitcan old batteries what you did with old batteries was throw them in a drawer, God knew why, it was just the Battery Graveyard instead of the one the elephants were supposed to have), bunches of rubber bands and wide red canning-rubbers, unanswered fan letters (she could no more throw out an unanswered fan letter than a dead battery), and recipes jotted on file-cards.

I had one letter from a person who fished my novel out of a trashcan, read only the Note, wrote me a fan letter, and (I suspect) threw the book back in the can.