I've just started re-reading the book called "Selling The Invisible" by Harry Beckwith. This is an awesome book written in 1997 before the internet become the dominant topic of coversation amongst marketers.
This book is peppered with real world examples of simple marketing concepts that reshaped many major companies and whole fields of service - as diverse as legal services, car rentals, airline services, hamburgers, pizza, you name it.
Many of these concepts go against the prevailing grain.
For example, in the chapter "The First Rule of Marketing Planning", Beckwith says almost everybody with the responsibility for marketing a company's products or services starts a new year (or new period) by saying "How do we sell more of this stuff?"
When what they should really be saying is "Is this viable anymore? Is this what the world wants?" In other words, "Is this what we should be selling?"

Stumble it!