Years ago, I asked my friend Steve Piersanti a question that had been bothering me.

Steve is the founder of Berrett-Koehler Books, the publisher of my book Accidental Genius, and someone who has seen more books succeed and fail than almost anyone I know.

I asked him, “What actually causes a CEO to buy books in bulk? You know, not buying five copies, but buying five hundred or even five thousand copies.”

I thought Steve would think things over. Instead, his answer was immediate. He said CEOs buy books in bulk for two reasons.

The first reason goes like this. A CEO reads a book and says to their leadership team, “You see this book? The expert who wrote this book says great organizations should be doing exactly what we’re doing here already. So you see, I told you this was the right way to go. I’ve been right all along.” Then they buy a copy for everyone in the company, so everyone can see that they were, in fact, right.

The second reason is a variation on the same theme, just with more bite. A CEO reads a book and says to their leadership team, “You see this book? The expert who wrote this book says great organizations should be doing exactly what I said we should be doing – only we haven’t been doing it. Why? You fought me on it. You questioned me. You slowed us down.” Then they buy a copy for everyone so the message lands with extra authority. “Maybe you’ll listen to me next time.”

What they don’t do is buy a book in bulk and say, “Look how wrong I’ve been. Please enjoy this detailed explanation of my mistakes.” People don’t buy books in bulk to confess error.

They buy them to immortalize agreement. It’s agreement between them and the expert.

Which leads to a useful, slightly uncomfortable insight for anyone writing a book. Your job is not to convert people who fundamentally disagree with you. That’s not how books move at scale. Books move when they give readers language and reinforcement for what they already believe to be true. You’re not writing for skeptics. You’re writing for allies, and for the people who read your book and say, “Yes, this is exactly what I’ve been trying to say.”

Now here’s the thing. This isn’t only about books. This is how ideas spread, products get adopted, and movements gain momentum. People don’t amplify things that make them look wrong. They amplify things that make them look right.

When does a leader share an article with their team? When it validates a decision they already made. When does a VP champion a new methodology? When it confirms the direction they’ve been pushing. When does someone evangelize a product? When using it makes them look smart.

The CEO buying books in bulk isn’t an edge case. It’s just how things work. We share things that make us feel understood. We pass along ideas that say, “Yes, that’s what I’ve been trying to say.”

So if you’re writing a book, launching a product, or trying to spread an idea, don’t aim at the people who don’t get it. Write for the ones who already do, and will recognize themselves on the page.