The word ‘commerce& is infrequently used in contemporary business speak and, when it is, it is typically as a somewhat archaic synonym for business or trade, or otherwise in the context of ‘e-commerce&. This book defines commerce by its traditional meaning, as the activity of transaction and exchange, and explores the corresponding interaction of human behaviour and economic interests. This book develops not only an understanding of the ambiguous interface between deals and relationships, but also the skills to manage it according to the situations and contexts in which it arises. The aim is to use advances on the fundamental phenomena of economic exchange (trust, reciprocity, altruism, reputation, etc.) and to apply them to a detailed explanation of the ins and outs of commerce. Of great interest to scholars and students of marketing, organisational behaviour and economics, this book attempts to bring together these advances to focus on the commercial phenomenon and propose a synthetic approach to the exchange relationship.