You may have heard the idea that people want to know only one thing, and that they only listen to one radio station, WIIFM, "What in it for me?" Books are no different than any other product.
While I am sure you like your book and you can easily see why people will want it, until you can give me solid reasons - benefits - to buy, and read your book, you have no sale.
You're asking people to invest not only their money to buy the book, but then their time to read it, so you better have some solid benefits that will compel them to do so.
What will your book do for me?
How will it improve my life, business, finances, health or whatever it is you're trying to do.
It must answer the "so what" question.
If you say that you'll learn all about the world of investment strategies, this is a fact, not a benefit. If I'm the reader and I read that, my question is going to be "So what?"
A benefit would be something like "and be able to build your retirement nest egg in less time."
The benefit statement would then be that you will, "Learn all the latest strategies and be able to build your nest egg in less time."
A more powerful way to phrase this would be, "Build your retirement nest egg in less time (benefit) by learning how to use the latest investment strategies." (fact)
These benefits, by the way, will go into your flyer, your sales page, your Web site and the back cover content, so invest some time completing this step.
Action step
Brainstorm at least ten, preferably twenty, key benefits a person will receive from reading your book.