In ten years. the situation of cities has changed completely. During the 1990s it was thought that many were dying or at the brink of bankruptcy (Detroit, for example). Since 2005, they have become hubs where new ways of living, working and playing are being created.

This development is primarily related to peoples’ proximity to each other (chapter 6, no 19). Because tablets and smartphones create and put into circulation a lot of data, the city becomes a Data Factory, a sort of open-air computer that serves as an ubiquitous platform for the exchange of Supply vs Demand (see the research of SENSEable City Laboratory, MIT).