One of the most common questions I get from potential authors is:

“I know I want to write a book, but I’m having trouble settling on the exact subject matter. How do I pick my book topic?”

There are a lot of ways to pick a book topic. I’ve written about other methods, but in this post, I want to explain one method that’s very analytical, directly tied to an ROI, and favored by many authors.

There are three steps to this process:

1. Decide the objectives for your book.

The first question you have to ask yourself is: What do you want your book to accomplish for you?

This question can confuse a lot of people, so the way we frame it for our authors is we ask them this very specific question:

Imagine it’s a year after your book has been published. What’s happened over that period to make writing your book worth it to you?

What this does is force you to think ahead and focus on objectives that are specific, measurable, realistic, and achievable.

Here are several popular (and usually reasonable) objectives that authors mention:

  1. Raise Visibility/Profile: a book is fantastic at helping an author get more visibility in any number of ways, like making it easier to get media or other forms of attention.
  2. Increase Authority/Credibility: a book is great at helping an author establish their authority and credibility in a field.
  3. Reach New Clients/Opportunities: a book is very useful at helping generate all kinds of new business and opportunities, in multiple ways.
  4. Obtain Speaking Engagements: a book is a necessity for becoming a paid speaker or even getting booked for any speaking engagements at all.
  5. Create a Legacy: a book can help establish a legacy and pass your story on to others.

Obviously, the details of each of these areas depend on your specific field and profession, but any of those can be very realistic objectives.

The goal you should probably stay away from is book sales. I’m serious—selling lots of copies of your book is usually an unreasonable goal for authors.

In short, here’s why: last year, there were almost 500,000 new books published in America. BookScan, the company that measures all book sales, says that only about 200 books per year will sell 100,000 copies or more. The number of books that sold 1 million copies last year is even fewer, probably close to 10 (and almost all of those were novels).

You can make a lot of money from a book, but that is done by using a book as a marketing tool. If you want to learn more about specific ways to use a book, I talk about 18 different ways to make money with a book here.

2. Figure out the audience you must reach.

Once you know what your objective is, then, by definition, there should be an audience that you must reach to accomplish that objective. Here’s an example:

Let’s say your goal is to speak at Human Resources conferences. In that case, the audience your book must reach is the people who attend those Human Resources conferences and the people who book speakers for those conferences.

Or, if you want to generate more business for your consulting firm that helps credit unions market their services, then you need to raise your visibility and authority with executives at credit unions.

Another example is if you want to become a more established thought leader in the change management space and have your ideas reach more people, then the audience is companies who need help with change management, and people who care about those ideas.

This is pretty straightforward and simple: the audience is dictated by the objectives you select for your book.

3. Ask yourself: What do I know that this audience cares about?

The final question is the key one: What do you know that is interesting and valuable to the audience you are trying to reach?

What they want to know about becomes the book subject. Here are some real-life examples:

Mark Laughlin wanted to help raise his visibility and establish his authority in the franchise coaching space, where he had a consulting practice. In order to do that, he needed to reach people who wanted to learn more about how to start and run a franchise, so he wrote the book How to Succeed in Franchising that explains exactly that.

Tyler Cauble wanted to establish his authority and generate leads for his commercial real estate business. In order to do that, he had to reach small business owners who were interested in finding and leasing space. He did that in a book called Open for Business: The Insider’s Guide to Leasing Commercial Real Estate that reveals all the information small business owners need to understand commercial real estate.

Jonathan Siegel wanted to raise his visibility and profile in the tech and startup scene, get speaking gigs, and generate deal flow. To do that, he had to reach tech entrepreneurs and investors. He did that by writing The San Francisco Fallacy: The Ten Fallacies That Make Founders Fail, which recounts Jonathan’s experiences building and selling a dozen software companies.

Check the Answers Against Each Other to Make Sure They Work

Once you answer the three questions, the key is to check each of the three against each other. If you don’t have anything relevant to say to the audience you need to reach, then you need to re-examine your book objectives to reach an audience you can help. Or, if your objectives are so broad they require you to reach an audience that is not within your grasp, you need to narrow them down to something smaller, so you can find an audience you can actually reach.

Everything ties in together.

The objectives create the audience.

The audience has their needs.

The book must provide value to the audience to reach the objectives you want to achieve.

It all ties together in a simple formula, and if you follow it, you’ll pick a book topic that provides value for both you and the audience.