If you’re thinking about writing a new book, have you asked: “Am I passionate about my book’s message?”

Passion underpins a successful book. The reason is threefold:

Passion provides more energy: A book takes a lot of energy to write, and on days when you’re confused or sidetracked, only passion can sustain you.

Passion compensates for uncertain payoffs: The payoffs of writing a book—money, ego gratification, business building—are not guaranteed. You need the electricity of passion to keep you charged.

Passion improves quality: Passion makes your writing better. It gives prose more color and insights more depth. Your best material will come from the heart, not the mind.

In my book Merchants of Virtue, I wrote about a group of amazing business people on the trail to the Holy Grail of management: sustainability. I was passionate about the book because I’ve always wanted to contribute to the environmental movement. The book contributed by showing how one company learned how to make money, deliver great products, employ happy workers, and be kind to the environment—all at the same time.

I worked on the book for over a year. I couldn’t have kept going on such a speculative enterprise if the book didn’t align my passions, expertise, and the needs of the market. Every book should do so—and then pay for itself in sales or spin-off business.

When financial rewards fall short of plan—if the market and your luck leave you in the lurch—a book you’re passionate about will still feel like a career milestone. You may not become rich, but at least you’ll have produced something of lifetime value. And in one way or another, you’ll also have produced a springboard for more lucrative work.

[Revised January 2020. Originally published April 26, 2011]