People talking is powerful.  You ask your best friend for a restaurant recommendation.  You ask your husband where to get the car fixed.  And, when you have a great experience, you tell everyone about it.  Word of Mouth Marketing by Andy Sernovitz draws attention to the power of people talking.  Businesses can utilize word of mouth marketing to let customers know about products, services, and specials.  However, if you want people to talk about your business, you have to give them something to talk about.  If you are wanting to practically implement this type of marketing in your business, church, or organization, I would recommend you read this book.  It is full of examples, as well as practical steps for implementation.  Since it has a lot of information, it takes a little longer to read.  However, you can grow in your understanding of marketing principles through this book.