I found this in the Judson Press guidelines.
“Successful publishers have developed specific ‘niches’ or areas of specialty. These niches are based on such related factors as the content and style of books, as well as their target audience(s). It is your responsibility to research and identify the publisher(s) best suited for the book you have in mind.
Consult publications as The Writer’s Market, Literary Marketplace, both of which can be found in most public libraries.
Browse publishers’ catalogs, either in printed form or online.
Visit local bookstores to determine which companies publish books similar to the one you have in mind.”
Couldn’t have said it better myself. Notice how they repeated studying the market before you write the book! I tried to do it backwards for many years and accomplished almost nothing.
-Contributed by Shirley Shibley