New information and communication technologies unquestionably brought about enormous changes that resulted in an ever-increasing networked society. Indeed, there is no area in the social and economic world which is unaffected by the recent advances. In response to these changes scientists from numerous disciplines teamed up in 1997 to lay a foundation for a common theory of networks. The objective was to gain a deeper understanding of the mechanisms behind social, economic, technical and other kinds of networks in order to develop a unified theory of networks. Such a theory would then guide...