I always admired the inventor of the microscope; he devised a tool to see what he didn’t even know was there. But he had a positive belief that something was there; I can see why the telescope was invented, because you can see the stars. Somebody just wanted a closer look. But how did Mr. Micro (I assume the scope was named after him) know there were germs there if he couldn’t see them? Why did he even think of looking for something he couldn’t see? Good question. Same thing with your book marketing: you have to look at yourself to find the resources you didn't even know existed, just as you have to look for a sale where you can’t see one.