If you don’t know what your target audience is it’s the group of people who are going to be reading your work, or the group of people you want to read your work.
Your target audience could be business people, moms, teens, children, etc.
But knowing this is important. Because it can help to know what audience that you have to start advertising to.
And I do think that this is something that you should be keeping in mind when you are writing the novel and not just after.
Because if your target audience is young children then some words you might not want to use. Same with teens who might not relate to things written from the point of view of a widowed mother.
So thinking about this as you write is a good idea.
But after you are finished writing is when you start expanding on what your target audience is. Is it teens? What age range? What gender? Is it written for adults? What Gender? What life experience? Mothers? Grandparents?
And on, and on, it goes.
The more you expand on this the better grasp you will have on where you want to start mentioning your book.
And this is important.
Because a book for adults will probably not get as many potential buyers on sites and blogs for teens. And the same for books for teens on sites and blogs dedicated to older readers.
So knowing your audience will help you know where to put your book on.
Not to mention that teens and adults are drawn to different cover types.
Most adults I know don’t really go for books with things aimed at teens and adults for things for teens.
So start working on what your target audience is. no matter what stage you are on it is always something to look at.