5. They address all correspondence using your main characters first name (Dear Frodo)
4. They ask how to find the portal to your world. (is that through a wardrobe?)
3. They use 1337 speak or text short hand when typing responses (UR s0 kewl)
2. They want you to call them for the feedback using their 1-900 number.
1. They end up at your front door wearing garb from your fictional world. (Nice trench coat)