I read a lot, but there's a moment in some books where the story grabs me and won't let go. I want/need/demand to know what happens, and I'm reluctant to do anything else until I find out. This morning I tore myself away from Jack Reacher's perils to do the work of authoring, but it wasn't easy.
Of course it's not the same author for everyone. Books that thrill me may leave you wondering what all the hoopla was about. Lee Child's work, Laura Lippman's, Victoria Thompson's-- are just a few that have that effect for me. Other times I slog through to the end with dedication to the duty of finishing the thing, but there isn't that spark of excitement, of wondering how the protag is going to get out of this one.
Here's a real thrill: some tell me they experienced that with my book. "I stayed up way past my bedtime" says one, or "I didn't get off the couch all afternoon because I wanted to know what happened." That experience is what every reader searches for, and it's the reaction that every author aims to produce. It won't always happen, but when it does, there's no better reward.