Even if it is a hoax, some of the things described in this novel are pretty creepy. The Real Life murders that actually happened in the house don't help matters.
For a parent, the idea that someone or something you can't stop is going after your children is horrifying...even if it's a demonic pig.
Demonic entity/"imaginary friend" Jodie's antics. First we have the babysitter trapped in a closet with no lock, who proceeds to pound on the door until her knuckles bleed. Then the light goes out and she's stuck inside for hours. When she's finally let out, the little girl she was babysitting explains Jodie wouldn't let her open the door.
Later, the same little girl is singing "Jesus Loves Me" as her mother walks down the hall. She comes in and we—but not her—see that the rocking chair in the corner of the room has been moving on its own as the daughter sings to Jodie. When the little girl complains her mother scared Jodie away and she went out the window, the mother bemusedly goes to look in order to demonstrate Jodie is imaginary—only to be greeted by two glowing red eyes staring back at her.
The black pit to Hell in the basement filled with unknown black pitch.