As a writer of fiction, I've had to learn how to dangle carrots in front of the reader. It's not as cruel as it sounds - I don't giggle with sadistic delight as I watch the frustrated reader try to grab the out-of-reach carrots I'm dangling. But, in fiction, I must give the reader something to reach for - some reason to turn that page.
I think of it this way -- rather than showing all my cards to the reader, up front, all at once, and rather than drop key information about characters or situations altogether, in one huge dose, I try and lightly sprinkle these key details throughout the story - bit by bit. It's partly to sustain the action/plot/conflict throughout 400 pages, but it's also to provide a more interesting story, overall.
Here's an example: Let's say you have a character receive a letter, gasp, then nervously stuff the letter into her pocket. This instantly produces the obvious questions for the reader: What's in the letter? Who's the letter from? Is it good news or horrible news? How will it affect the character's life? You've just dangled the carrot. And if you can hold off and have her not open the letter for a chapter, or even a few chapters, then you've carried the suspense even further, making readers even more eager to have their questions answered.
Call it a hook, or a gimmick, or even passive-aggressive manipulation, lol - but whatever you call it, you can't deny that some level of suspense can keep a reader interested. And, it can keep things interesting for you, the writer, as well. Because, trust me, if you're bored with your own work, the reader will be just as bored.
The textbook from which I teach (Crossroads) calls this carrot-dangling technique "developing dramatic questions." Basically, you want the reader to have certain questions about characters' pasts, or their future decisions. Because questions make readers curious. Curious enough to read on. And, even better, it makes them think for themselves. You're not spoon-feeding them and over-telling the plot. Instead, you're giving the readers a chance to form their own opinions and suspicions. They become more actively involved, that way...
One word of caution - there's a difference between dangling carrots and flailing them about with a devious look in your eye, taunting the reader mercilessly. Dangling carrots is a way to create suspense. But if readers can overtly see it as manipulation, if they can tell it's just a gimmick, "stuck there" to produce suspense, it won't work. It's got to feel absolutely natural - part of the story itself, worked in seamlessly. Because if readers feel manipulated, if they "see" you dangling carrots in an obvious way, it'll only make them frustrated. And rather than read on, they might just close the book altogether.