This book contains the refereed proceedings of the 4th International Conference on Software Business (ICSOB) held in Potsdam, Germany, in June 2013. The theme of the event was "e;From Physical Products to Software Services and Solutions."e;The 15 full papers, seven short papers, and six doctoral symposium papers accepted for ICSOB were selected from 44 submissions and are organized in sections on: software business models and business process modeling; IT markets and software industry; IT within organizations; software product management; cloud computing; entrepreneurship and startup companies; software platforms and software ecosystems; and doctoral symposium.