If you've ever wondered about the inner mechanics of a customer/consumer's mind when it comes to buying goods and services; and wondered at the inner mechanics of any seller's mind (any person selling goods or services) Sean D'Souza's book, The Brain Audit: Why Customers Buy (and Why They Don't), is a good starting point. It makes you think of problems and solutions in a whole new way. And it explains how easy it is to talk past each other, without realising it.