Early on I thought a feature list was marketing. "My dog is bigger than your dog" never really sells anything. Communicating tasks performed is a leg up but still very "me too." Self anointed fuzzy words like "new, improved or innovative" are overused and without substance. If I hear anybody from Microsoft talk about "innovation" again I'll barf. How can a product be innovative if it doesn't even work? What's missing here? The answer is "emotional essence" that speaks to an inner desire.
I remember vividly the day I finally got it. In a speech Paul Revson gave, think Revlon, he said "I don't sell cosmetics, I sell hope." Talk about understanding why someone buys your products -- Wow. Your sales proposition doesn't have to be product capability based. It should deal with need or desire. Every time I develop a marketing campaign or have any public communication that piece of wisdom jumps forward in my mind. If I haven't achieved that level of insight I'm just not done yet -- grade incomplete. It's not always easy to reach that insight. Like chess you need to think a number of moves ahead. In this case moves your customer will or wants to take. Clients frequently describe a problem not by what the problem is but instead what they think is a solution. It's hard to get at the real issues but it's well worth the effort. Finally we must think like our client's customers to find the "emotional essence" that cinches the sale.