Despite a general consensus about the economic impact of research conducted at universities, the mechanisms through which this is realised remain less clear. Scholars have focused on particular “output” measures as indicators of economic success such as patents, licenses and the creation of spin-off companies. However, it is argued that such indicators hardly measure 10% of the knowledge transfer that takes place. This means that most of the knowledge is transferred in various other forms of collaborations between university labs and industry, usually labeled as ‘contract research’. This paper attempts to put formal transfer mechanisms in context with contract research performed by university labs. Two main questions are of particular interest: First, what is the relative importance of contract research, licensing and spin-off creation, both strategically and in terms of actual output? Second, how has the nature of contract research evolved given the strong professionalisation trend at the technology transfer offices?