The chapter provides the background on the economics of this book, on the ‘sharing economy’ and how Uber can be assessed as an economic agent. This book understands markets as open-ended undetermined series of exchanges between a potentially unlimited number of agents. These agents engage voluntarily in the different market processes without knowing more than the other agents but judging their own beliefs, preferences and costs subjectively. Agents use the market processes in order to learn about other agents’ beliefs, preferences and costs. Market processes are cooperative actions. Whatever might be labelled the sharing economy relies on these market processes and does not in any way fundamentally change them. The sharing economy is not different from the traditional economy; to the contrary, it applies and broadens the application of market processes and individual actions. However, the role that technology plays is important. With the development of online networking, e- and online payment methods as well as individual online mobility, many business models gain scale and scope. Technology often makes it possible to diminish costs of participating in a market process, to learn quickly or gather information in a timely manner as well as to scale up some market processes. Uber, in due entrepreneurial spirit, seized this opportunity and turned it into a successful business model.