I obtained this from the book, "The Challenger Sale," by Matthew Dixon and Brent Adamson.
The question you have to ask yourself is very simple, but takes a long time to answer. You have to give a lot of thought to it, but once you have it, you will know how to differentiate yourself from your competitors.
The question is:
"Why should your customers buy from you over anyone else?"
Work on this, since this is the only question that matters.