Know your audience
Your customers may not believe what you do. They may not see the world the way you see it.
Where do your clients come from? What influences their likes and dislikes? Where do they spend their time online? What do they do in their free time? What do they wish for? What will they never admit out loud?
Understanding your audience is key to writing well, selling better, and creating more effective products.
How do you know what your audience wants? Listen. Observe. Research. Repeat.