The sales of paperback non-fiction have been declining and it's easy to assume that this is the result of the advent of e-books. However, figures provided by Neilsen Book at a recent digital publishing conference suggests that the decline started before that.
The most likely reason is that so much information is available free on the internet. People who formerly might have bought a reference book look to Wikipedia and other online sources now.
I think this suggests an important lesson for anybody who is writing a non-fiction book, namely that you have to make sure that either the content or the presentation of your material is different from what people can find easily on the net.
Here are a few ideas on how you could differentiate your non-fiction book.
DECIDE: BEAT THEM OR JOIN THEM?
Authors have responded to the rise of internet content in two ways: the "if you can't beat them, join them" strategy, which entails having bite-size content, colorful graphics, sidebars with comments that resemble Tweets, etc.; or the "do what they can't/don't do" approach, going in-depth and being unashamed about demanding the concentration of the reader.
I believe that books that aren't clearly in one camp or the other are less likely to succeed.
BRING YOUR PERSONALITY
Bring your personality to the subject. The one thing you can offer that nobody else can is your unique experience or perspective. When appropriate, include anecdotes and other personal touches.
A good example of this is the Freakonomics books, which make a traditionally dry topic (economics) entertaining and bring in the authors' experiences and views. The first book was subtitled: A Rogue Economist Explores the Hidden Side of Everything.
FOCUS ON THE DIFFERENCES
In your marketing, including the title, cover image, blurb, etc., reflect what makes your book different. Again, Freakonomics had a cover very different from that of most books on economics.
THINK ABOUT SEQUELS
Finding people who buy your book is hard work, so think ahead to how you can keep them and what else might interest them. It could be a sequel or just a related topic. If you put your website address in the book and offer the reader an incentive (e.g., an extra chapter) for signing up, you'll have a list of people to whom to market your next book. If you already have the next book in mind you can mention it in the current one.
Here's an example, continuing on from Freakonomics, of a book that gives more of the same:
Then they went on to a book that uses what went before but goes off in the direction of self-development:
CONSIDER OTHER FORMATS
Rather than assuming that a book is the best format for your project, consider whether other ways of presenting it might be better or easier to market. For example, although I've written a number of books on writing, my next project will be an online course. That allows me to integrate videos, audios, quizzes, etc. I will also be offering free webinars to people who buy the book, which will allow me to interact, answer their questions, and of course let them know of future projects that could be of interest to them. This creates a product with added value to the user, and also allows me to charge more than I would for a book.
All of these tips have one thing in common, namely that they encourage you to be creative about how you approach a marketplace in flux.