The Best Service is No Service (2008) by Bill Price and David Jaffe is a wonderful book about how to improve customer service. Their ideas are simple in concept but difficult to implement properly. The idea is this. If companies understand why customers contact them they should be able to identify "triggers" for inbound contacts. If companies proactively contact their customers with information that customers want then they should be able to eliminate a large proportion of inbound contacts.
Most of the book gives solid advice on how to implement this seemingly simple idea. It also points out some of the difficulties that companies will encounter, one being that the business area that is catching all the incoming flak - the customer service area - has little organizational pull in getting effective incoming contact mitigation implemented.
I work at the IVR and contact center end of customer service, and I can vouch for the fact that a lot of incoming calls could be prevented simply by communicating more effectively with customers - giving them information they need before they call and ask. Companies are just dying for design approachs to customer service, and this book is a good place to start.