The single most important thing you need to write a great book is:
If your book has a great hook, it is much more likely to sell well, and it might change your life forever.
Even cooler, if you get your hook right, you’ll be clear on who your ideal reader is and the impact your book will have on their life. You’ll know the problem they have and how you are going to solve it – in a way that nobody else is helping them solve it right now.
This makes it easy for a reader to see why they need your book, and it makes it ultra-easy for people to share your book with others because they can clearly say why someone should read it.
From “Self-Publish & Succeed: The ‘No Boring Books’ Way to Write a Non-fiction Book That Sells” by Julie Broad