Analyze the content of your book vs the audience profile.
Your content will determine the audience of your book. Who will be interested in the kind of content you are publishing? Narrow down the persona, such as age, gender, hobbies, interests, the industry they belong to (if applicable).
Expanding to the secondary audience.
Once you have identified the primary audience, expand to the secondary group. Ex. If you are publishing a cookbook for mothers, a secondary set of audience would be restaurant owners, food bloggers, etc. Now, many of us will not have an effort in targeting a secondary audience, but if you do this technique, you’ll be surprised by how big they contribute to the total sales.
Check out the competition.
Identify similar books in the market and look at their audience. Find out the top-selling books that would be in the same category, genre, or niche because you probably share the same audience and readers. Study where most of their audience come from.
Social Media Assessment
As soon as you have identified competitors and books in the same category, look at who is following them on social media. Identify online communities and Facebook groups who may be interested in your book.
Before you even send your book out to the market, it is important that you identify the set of audience you will have. This is an important factor in implementing a successful marketing strategy for your book.