This pioneering study looks across key trafficking crimes to develop a social theory of transnational criminal markets. These include human trafficking, drug dealing, and black markets in wildlife, diamonds, guns and antiquities, The author offers an in-depth analysis of structural similarities and differences within illicit trade networks, and explores the economic underpinnings which drive global trafficking. Revealing how traffickers think of their illegal enterprises as ‘just business’, he draws broader lessons for the ways forward in understanding criminality in this emerging field.