I'm an advocate of not starting a project--especially a large project--unless you know it has a chance of success. Failure's good; we learn from it. However, writers and aspiring authors, like most people, have no time for failed project into which they invested hundreds of hours. Therefore, I rarely, if ever, write a word of a self-published book or a book I hope to traditionally publish unless I evaluate that book idea's success potential first.

When we come up with ideas for books and want to simply sit down and begin writing, that’s good. It means we have enough excitement about our ideas to actually start and even finish projects. However, that excitement may cause us to begin too quickly.

In fact, not every book idea deserves to be turned into a book. Some ideas make better articles or essays simply because you don’t have enough content to produce a full-length book. Others might be appropriate for a book but only your friends and family  will be interested in reading it.This means, your idea might only have a market in your immediate circle of influence. Or maybe your idea simply isn’t unique—the market already has too many other books just like it.

That's why it's worthwhile to evaluate your book idea’s success potential prior to writing a word—or very many words. Do this by using the publishing industry standard—the book proposal—as your guide. Take your idea and view it through the lens of a book proposal, and you’ll know quickly if it has the ability to thrive as a print book or ebook. Evaluate your idea as any agent or acquisitions editor might if they were to read your book proposal. There's no need to write a proposal; just go through what I call the proposal process.

Book proposals contain a variety of sections. The most important ones will quickly tell you if your idea is viable:

• Markets: This book proposal section asks you to describe your book’s markets—large groups/numbers of people who might be interested in and purchase your book. These are the people who will find your book relevant for some reason. If your idea has appeal to large markets, many markets or even one small niche market, it might be a good idea.
• Competing Titles:  In this proposal section you look at the previously published books and compare your book idea to them. If you feel your idea is unique and fills a “hole” on the shelf of a brick-and-mortar bookstore as well as an online bookstore, then your idea gets the green light.
• About the Author: In this section you actually write a bio of yourself and discuss why you are the best person to write this book. However, this is a chance to compare yourself to the authors of the competing books and ask yourself if you can compete with them. Are you unique? Do you have the credentials necessary? If so, then your idea passes on to the next part of the proposal process.
• Mission Statement:  Do you have a reason to write this book? Is it your purpose or mission? Will your book serve a purpose, too? Will it add benefit and offer value. If you can answer “yes” to these questions, your idea might be a winner.
• List of Chapters: Create a table of contents for the potential book. Does it look like you have the makings for a book? Can you see an actual structure and imagine content for a full book? If “yes,” proceed!
• Chapter Summaries: Describe each chapter’s content. If you can summarize each chapter and then feel certain you really do have a book inside you that needs to get out,” and it all makes sense on paper, get writing!

A book proposal contains more sections, and all of them prove helpful to the “proposal process.” I suggest you go through all of them, but the sections above prove the most essential ones for evaluating your book idea. If you take the time to go through this evaluation process, you’ll find yourself writing many more successful books—books that sell to readers and to publishers—and ending up with a lot less book manuscripts that you shove in a drawer or save on your hard drive for eternity.