Business books are everywhere. Everybody and his brother’s consultant insists they have an idea for a book that will change the world. Or maybe they’ve already written and self-published the book, which they hand out as freely as a business card.

“A lot of great business books don’t make it,” says Kevin Cashman, a leadership consultant with six books to his credit. “The average business book used to sell 5,000 [copies]. Now they sell 500.”

Cashman, a senior partner with the Minneapolis office of Korn Ferry, has fared better. His two best-selling titles, Leadership From the Inside Out (first published in 2000) and his latest, The Pause Principle: Step Back to Lead Forward (published in 2012), have sold 250,000 copies combined. He says that the books have resonated because they were born out of his experience in the trenches consulting with CEOs. He noticed consistent trends. In an increasingly hectic business world, the constant pressure is to frantically keep doing more. Cashman’s Pause Principle makes a counter-intuitive case for taking a step back to see the big picture. Cashman says that he “tested out the concept” for the book for 10 years before he wrote the book.

“Strategy is stepping back to envision the future,” he says. “People say they don’t have enough time, and then the company can be destroyed. … That’s the trap we fall into..”

Cashman believes authors should approach books like a business. “I had PR support for Leadership From the Inside Out for seven years. Too often someone writes a business book and they’ll have just a three-month campaign,” he says.

In the wake of Leadership From the Inside Out, Cashman’s business expanded beyond Minneapolis to serve international clients. In 2006, he sold his firm LeaderSource to Los Angeles-based Korn Ferry.

How important was the book to Cashman’s business? He recalls that one corporate client was routinely buying 150 to 200 books a year for its internal leadership development programs. Later, the company tapped Cashman as a keynote speaker for an event.

“Now that account 10 years later is $9 million a year in consulting revenue,” says Cashman, who declines to name the company in question. “Where’s the real revenue? You can’t even compare the two.”

Financial advice columnist Gail Marks-Jarvis recalls that she had no grand ambition when she wrote her retirement planning book. “I just wrote it because I thought it would help people. I get thank-you notes from people telling me that it has.”

MarksJarvis wrote for the St. Paul Pioneer Press for more than a decade before she joined the Chicago Tribune in 2005. Her book, Saving for Retirement (Without Living Like a Pauper or Winning the Lottery) debuted in 2007; an updated, second edition came out in 2012. She admits that she doesn’t know how many copies her book has sold. “You don’t make huge amounts of money writing a book.”

Sam McNerney is executive editor of 250Words.com, a website spotlighting business books. The site is owned by Simon & Schuster and is “publisher agnostic,” as McNerney puts it, about the books it covers. He says that the best business books are driven by the same elements that make any book a good read: a strong narrative with compelling characters. “The facts never speak for themselves. You need to tell a good story,” McNerney says.

Cashman is working on two books right now, but he’s in no rush. Books take time.

“What you don’t want is it to be an expanded article,” he says.