Here are some criteria on which you can evaluate your ideas.
- Audience size. How big is the audience for your idea? Big audiences will have more potential sales, but small, focused audiences are easier to reach and are likely to be more connected to each other.
- Timeliness. Is this an idea exactly on-point for a current trend? Ideally, the trend yo write about will be peaking a year from now when your book is done. If you’re writing about an idea that super-hot right now (like AI, for example), the market may be crowded with other books on the topic by the time yours comes out. The alternative is to write an evergreen book, which is harder to promote but will stay relevant far longer.
- Your expertise. It’s great to write about what you know, and when you do, you can usually complete the book more quickly. But if everyone else already knows a lot of what you know, you’ll have to do research to expand your knowledge. If you’re writing about an intriguing idea that’s not within your usual circle of expertise, expect a long process of learning and developing the idea.
- Case studies. Do you have access to people whose stories will bring your book to life? If you don’t, how will you find them? How will you make sure you’re not telling the same well-worn stories as everybody else? (Henry Ford and faster horses, anyone?)
- Idea size. A small idea may be too limited to support a book-length treatment. A vast idea may be too large to cover in a single book of 65,000 words or less — and bigger books are often not just more time-consuming to write, but harder to sell. The best idea is one that’s simple to state but has enough elements and consequences to fill a moderate-sized volume.
- Impact on your career. Will the book generate clients and speaking engagements? Will it boost your visibility? Will it extend your reputation in a current field, or expand it into a new area?
- Differentiation. How is your book different from all the other books on the topic?
- Salability to publishers. How hard is the idea to explain? How sexy will it appear to agents and publishers?
Making a decision
After evaluating these criteria, figure out what book best balances the effort you’ll put in and the benefits you’ll gain. A hard-to-create book on a powerful idea with a healthy audience could boost your career for years. A quickly-assembled book on a topic you already know well could instantly put you on the map. It’s well worth the effort to carefully match up the work the book will require, your goals, and your chances of success.
It’s far better to understand your best path now then to suffer the pain of realizing, halfway in, that you made the wrong choice.