It's been about six months since I read a novel where the main character was reading a comic or manga, and his favorite character was killed off. He complained to the author, who replied that the character died because the readers didn't care enough. The author then challenged the MC to try and do better, and suddenly the MC finds himself transported to the comic/manga world as a mob character. Now, he must do everything he can to make readers remember him, so that he can keep his character alive.
I know this is a long shot, but I'm hoping someone can help me find the title of this novel. If you know the name of the book, I would greatly appreciate it! Thank you in advance for your help.