Even after Comiket, where do you think those doujinshi book go? They become available via online or if it's from a rather popular author, they can put it into your local bookstore unofficially. Like how you put your homemade crackers to your local restaurant.
Man, the story really feels like jumping to bullet point over other bullet point. There is no substance in it, they just say stuff happen and rarely shows it. MC slaughtering the bandits? Just show that he already killed it without the action. So fucking lame