As the thinkers have said, you should strive in all situations to know yourself and know your enemy. Most of history's great thinkers, however, were not in business. In business, you have to know your customer and understand how your company interacts with him or her. The current term for this is customer relationship management (CRM), and The CRM Handbook is the best textbook for managers on the mechanics of CRM. It's a standout in a field that's filled with squishy books that go on at length about how important CRM is, but which lack details. Jill Dyche provides lots of factual information, real case studies, carefully considered commentary, and reasoned criteria with which to evaluate CRM products and strategies. Though you'll certainly want to supplement Dyche's work with vendors' product literature and implementation proposals, you'll get a lot from her carefully researched book. Dyche devotes some of her (fairly slender) volume to CRM...
