NEED to know
INTERESTING to know
Gee, you can almost feel the difference just saying each one. Guess which one flies off the shelf?
Let's say you're in the bookstore perusing the health shelf because you always have a sore back. There's one prominently featured book titled A History of Back Pain: Medical Advances for Those in Pain. The book next to it is titled NO MORE BACK PAIN. Which one do you pick up?
Or, you're a constant dieter. You're addicted to that shelf in the bookstore. One title: WHY ENDLESS DIETS DON'T WORK. Next to it: YOUR LAST DIET: You Can Finally Meet Your Goals. Which one do you pick up?
Or, you're still trying to learn to budget after all these years. You go to the finance/business bookshelf. One book titled THE ESSENTIALS of BUDGETING catches your eye: Next to it is HOW TO LIVE WITHIN YOUR MEANS WHEN YOU NEVER HAVE.
The "need to know" combined with a promise to you is almost irresistible. First, the title speaks to you directly about the problem you want solved. As soon as you see the title, you know you need to know what it has to say. Second, it makes a promise to truly solve your problem, once and for all. Whether it ultimately does or not, it's the title and the promise that make you buy THAT book instead of the others. You can buy the "interesting" ones some other day. Today you'll buy the one you NEED to have.
If you're working on your nonfiction book, outline, or proposal, stop and make sure you are casting, titling, and writing the book that solves the NEED TO KNOW. You can have "interesting" things sprinkled throughout the book, but you're only going to get your potential readers to choose yours if they NEED to know it and want what you promise.
And this is as blessedly brief as I can be on the topic. :-)