Much about success is just the result of simply the ability to follow up, follow through, and finish what we started.
The young athlete who aspires to greatness, generally speaking, learns a number of things from several different coaches. The first one taught him the fundamentals; the second one instilled discipline in him and taught him more of the techniques that must be mastered to excel.
When you are truly interested in other people, you will learn what they are interested in and if they have a need for your product. If they like you, and most people like folks who take an interest in them, they'll help you find people who do need what you have to sell, even if they don't.