Most book marketing today is done by authors, not publishers. Publishers have managed to stay afloat in this worsening marketplace only by shifting more and more marketing responsibility to authors, to cut costs and prop up sales. In recognition of this reality, most book proposals from experienced authors now have an extensive — usually many pages — section on the author’s marketing platform and what she or he will do to publicize and market the book. Publishers still fulfill important roles in helping craft books to succeed and making books available in sales channels, but whether the books move in those channels depends primarily on the authors.
My friend — also my editor and publisher — Steve Piersanti, who founded and runs Berrett-Koehler Publishers, has been tracking sales and other key publishing industry data for many years and frequently updating it. This is from his most recent report.