Why do You Keep Turning Pages?

I've been thinking a lot lately about what makes a story really compelling -- what makes a story capture a reader, draw the reader in, and leave the reader simultaneously satisfied and wanting more. And as I've considered this idea, I've thought about some of the books that have really impacted my experiences as a reader and some that I know have impacted others. Here's what I've decided: You have to give the reader enough, but not too much.

What the heck?

I think you have to give the reader enough of a start that he or she takes what you've given and runs with it, creating a visual image of the protagonists and the antagonists, imagining the scenes and the conflict, and hearing the dialogue in his/her own head. You have to give enough direction that it plays out ALMOST like a movie in the reader's mind.

Rob Parnell suggests it's about questions -- posing questions in the story so that the reader must keep going to get the questions answered. A refreshing reader's perspective on what makes her keep turning pages is offered by Laura Miller of Salon.com.

What about you? What are some of the most compelling novels you've ever read? Why were they compelling?