Th e book so far has focused to a major degree on sellers. Some aspects, such as contract selection and the entire contracting process, would be interesting for both sellers and buyers. Th e following contents are more of concern for buyers who need to manage complex and often highly dynamic project support networks (PSNs). Th ey should nevertheless also be of interest for sellers. One of the major success obstacles and profi t destroyers is poor project management on the customer side. Another reason is that a project manager working for a prime contractor is simultaneously a contractor to the customer and a customer of the subcontractors. In project management under contract, it is often impossible to say: “Th is is not my business”.