It's one thing to write a book, it's an entirely different thing to write one that's a saleable, viable, marketable product. Ensuring the success of a book is something even the biggest publishers have never been able to guarantee. Mitigating circumstances, flash trends, and world events will all affect buyer preferences. That said, there are still ways to leverage the sales-factor in your favor and here's how you do it.
1. Know your readers. We're not just talking about whether your readers are male or female. You'll want to know myriad factors about your audience. How old are your readers (age range)? Are readers married, single, or divorced? Where do your readers live (generally)? What do your readers do for a living? What other books/publications do they read? Develop a profile that includes where they shop, what clubs they belong to, etc.
These elements will help you incorporate these aspects into your book *and* help you unearth salient marketing opportunities (i.e., publications and stores).
2. Know your market. What's the market like for your book? Is there a trend out there you're positioning yourself toward? Are you reading all the publications related to this topic/trend? Are there any "holes" out there your book could fill? What's the future for this market/topic? For example, let's say you're a fiction writer looking to publish chick lit. Go to any bookstore and you can't help but spot the cutsie, pink, cartoonish covers. Many thought this trend was dying out, but it has recently seen another surge. What do you know about trends related to your book/topic/audience?
3. Similar books. What else has been published on your topic? Have you read all ten books in your category? If you haven't, you should. You'll want to know everything you can about what's out there and how it's being perceived in the marketplace. It's never a problem having a similar topic. When I published No More Rejections - Get Published Today, I knew there were other books out there on marketing. I read them all--then angled my book differently.
4. Getting and staying current. What's going on in your industry today? What are some hot buttons? What are people looking for? What's next on the horizon for this topic/audience? If you can't seem to gather this information through traditional channels, why not survey your target audience? There are a number of places to run free surveys, Survey Monkey is one of them: http://www.surveymonkey.com
5. Follow the media. What's the media talking about these days? Keep track of media buzz--what they're paying attention to and what they're writing about. Delve beyond the front page of your paper to the second or third page and see what's filling the pages. If you can get your hands on out-of-state papers, do a comparative review. Do you see a trend in coverage? Is there something that seems to be getting more buzz even if it's on page six?
6. Talk, teach, listen. One of the best ways I've found to get in touch with my audience was to teach a class and do speaking engagements. When I was putting together my book, Get Published Today, I found that the classes I taught provided valuable information for creating a great book because they put me directly in touch with my audience!
7. Timing is everything. When do you plan to release your tome? Are you releasing around a holiday or anniversary? Could you take advantage of any upcoming event and/or holiday for your book launch?