Let’s start by answering this question with what you should not
put on a book cover. Your cover will be rejected by booksellers if you have a
URL (website address) or if you promise something that is not included with the
actual book that is purchased (such as a companion study guide or an audio book
that must be retrieved elsewhere).
You should also avoid any art that is not PG or below, even if it is a steamy romance or erotica book. The reason is simple: your cover very well may get rejected by booksellers for being too risqué and your book could also end up in “the dungeon,” where it is excluded from search engines. But this advice even applies to textbooks, art books, photography books, and any other book that may have a tastefully artistic nude or other medically accurate image. Remember, these decisions are almost always made by a machine algorithm and getting the live customer support to have a rational discussion about it may be very difficult. You want people to find, see, and buy your book. You can do that with a PG cover no matter what the topic is.
One author in our group even had a hard time with a pencil drawing of an attractive woman only covered by a small towel. She was willing to do battle with customer support, and eventually even had Jeff Bezos’ office personally involved, and it was resolved in her favor. However, her persistence and results are probably not easily replicable for most.
What else, other than the author’s name, title, and subtitle should be on the book cover? If you have a foreword, you will probaly put that author’s name on your book cover. In my book Viral Leadership the foreword was written by Randy Dobbs, the former CEO of General Electric Capital (ITS). That is an important endorsement. I want prospective readers to know that heavyweight business executives like Mr. Dobbs appreciate my work. So, the cover has Foreword by Randy Dobbs and then his title. In this case, Former CEO of General Electric Capital, Information Technology Solutions. If the person who wrote your foreword is also an author, you might put their book title instead (“Foreword by Santa Claus, author of How to Make Christmas Work”).
Credibility phrases are taglines below your name that tell the reader you have credibility. They are optional and do not have to be on a cover. But several of my books I do have Licensed Marriage and Family Therapist spelled out below my name (notice I do not have the initials LMFT after my name on the cover. Please do not use professional initials: they clutter a page, and many people have no clue what the collection of letter means. It makes a book look amateur and self-published.)
A few of my books have a credibility phrase that lets them know I am an expert in the field because I have written other bestselling books. Below my name, instead of my professional title, I have chosen to put, “Bestselling Author of ______,” filling in the blank with a related title.
Another credibility phase I have used is one that claims my position as an expert. For example, on two of my self-hypnosis books, the credibility phrase says, “America’s #1 Leading Self-Hypnosis Expert.” I want you to note that this is a marketing phrase, and its purpose is to instill in the prospective reader credibility so they buy my book. There is no actual award of this type. It really is arbitrary and cannot be measured. Now I do have millions of people who have watched or listened to my self-hypnosis recordings (which clearly puts me near the top of content producers), I have written several best-selling books on the subject, and I have trained perhaps more people in hypnosis than anyone else in the past 20 years. But the claim is still subjective. You can make a bold claim like this. You should be credibly able to make such a claim but realize that in marketing it is the bold who finish first. So go bold and stake your claim to expertness if you think it will help you sell the book (which in and of itself, validates that expertise).
