A lot of manuscripts slide across my desk each week, which shouldn’t surprise anyone seeing as I run a publishing house. After all these years in the business, I can identify why a particular book draws me in and where another immediately goes off the rails. I mean, I can point to the exact place, nearly in my sleep.

Usually, the deadly issue appears in the first few pages of the introduction, and nine times out of ten, it involves the lack of a core message.

Your book needs to have a core message that gets supported by stories, lessons, observations, research, and examples. This core message is what holds the book together. Like super glue.

Definition of Core Message

The core message, if you’re looking for a definition, is the fundamental takeaway or primary insight you want readers to gain from your book. It’s often broader and more universal than the thesis (the central argument or main idea of your book). It’s a specific claim or position that you aim to prove or explore throughout the work. While the thesis might be an argument, the core message is the essential truth or principle you’re conveying.

Now, if you’ve been around longer than a hot minute, you’ve probably heard me talk about the need to spell out a clear solution to an urgent problem if you’re writing a prescriptive nonfiction book. And avoiding the misguided attempt to solve every problem known to man all in one go so you can dazzle mankind with the breadth and depth of your knowledge.

But this is different. This is more about the position you take. Where you come down on a topic. Making that a nice concise statement.

For your book to be super readable, attractive enough to turn readers into buyers, you need to be able to describe the big idea your book addresses in a matter of a few sentences. We need to know, right up front and throughout, the argument you mean to make and support.

This core message is often built into what’s called your book hook, which is a fascinating idea that draws your reader in instantly, makes them want to know more, and convinces them that your book is exactly what they’ve been looking for. While the core message is the fundamental takeaway of your book, the book hook is the attention-grabbing statement that entices readers to pick up your book in the first place.

I know! All these definitions!

Examples of a Good Core Message

Now, if you want to see exactly what I mean, there’s no better teacher than Nathan Lozeron of The Productivity Game. I follow him on YouTube and you should too. This dude gets to the core message of bestselling non-fiction books like nobody’s business.

You may recognize many of the books he breaks apart with a wrench and screwdriver.

*Note: Each of these authors has enough expertise to fill 20 books, but they’ve identified one over-arching message they mean to support, which will attract someone with that problem or concern right away. Everything, and I mean everything, serves to expand upon the idea and drive the message home.

The Confident Mind by Dr. Nate Zinsser:

Core Message: Confidence is that feeling that you can do something (or that you know something) so well you don’t have to think about how to do it when you’re doing it. That skill or knowledge is in you, it’s part of you, and it will come out when needed if you let it.

So Good They Can’t Ignore You by Cal Newport:

Core Message: The people who love what they do for a living have a craftsman mindset, not a passion mindset. The things that make great work great (creativity, impact, and control), are rare and valuable. If you want them in your career, you need rare and valuable skills in return.

Just Keep Buying by Nick Maggiulli

Core Message: If there was just one factor you could use to guide your investment decisions, it should be: most markets go up, most of the time. So Just. Keep. Buying.

Never Split the Difference by Chris Voss

Core Message: You can get what you want in a negotiation without compromising. Make the other side feel like they were treated fairly using tactical empathy. Empathize with their situation then get them to empathize with yours.

Grit by Angela Duckworth

Core Message: Learning to stick to something is a life skill we all must develop, but grit is not all about stubbornly pursuing—at all costs and ad infinitum—every single low-level goal on your list. You should try hard, but don’t beat your head against the wall attempting to follow through on something that is merely a means to a more important end.

I mean, do you see how narrow the focus of each book is? How clear and exact?

Yah, that’s not that easy to do. I know. I do this for a living. And if you’d like to nail down this core message, this one big idea that will drive your entire book, maybe we should talk. I’ve also got an upcoming masterclass on the topic that might light your fire. Stay tuned.