Define "Scary"

I have been sharing a lot of "scary" stories lately. 

Most teachers who book me for a storytelling performance in October say that they want scary stories, but not TOO scary.   

One of my favorites is the Belly Button Beastie, a Japanese folktale about a boy who has his belly button stolen by a monster that turns out to be friendly.

When my daughter Emmaline was four I read the story of the Gingerbread Man to her.  After the horrible demise of our hero, I asked Em if this story was scary.  She rolled her eyes (just like a teenager!) and said, "Mom, he is a cookie."

I want to be sensative... where is the line?