Harrison Smith is a PhD Candidate at the University of Toronto’s Faculty of Information. His research focuses on the political economies of geospatial media, surveillance, and mobile digital culture. His thesis explores the economic and cultural implications of location data to inform new methods of audience targeting and clustering for mobile and location based marketing. Harrison is also a research assistant for geothink.ca, a Canadian geospatial and open data research partnership between Canadian universities, municipalities, and the private sector. There, his research focuses on the economic potential of the geospatial web and the sharing economy.

Michael Hardey^† was a Reader in Medical Sociology at the Hull-York Medical School (HYMS) until his untimely death in March 2012. Prior to this he worked at the Universities of Newcastle, Southampton, Surrey and Essex. He made huge contributions to the early literature on e-health and digital sociology more generally. He also worked on the sociology of lone parenthood. He was the co-author (with Roger Burrows) of ‘Cartographies of Knowing Capitalism and the Changing Jurisdiction of Empirical Sociology’, a chapter published in the first edition of this Handbook, important elements of which remain in the chapter updated for this second edition.

Mariann Hardey is a lecturer and member of the Marketing Group at Durham University Business School, UK. She is a social media professional and academic and the BBC North East commentator for social media and digital networks. She read literature at the University of Sussex and later undertook a research MA followed by a PhD at the University of York. She has published articles in journals such as Information, Communication & Society, the International Journal of Market Research and The Open Medical Informatics Journal and has also published numerous book chapters.

Roger Burrows is currently Professor of Cities in the School of Architecture, Planning & Landscape at Newcastle University. Prior to this he was a Pro-Warden and Professor of Sociology at Goldsmiths, University of London, UK. He has also worked at the Universities of York, Teesside, Surrey, East London and Kingston. A sociologist by background he has published over 130 articles, chapters, books and reports on digital sociology, methods, urban sociology, housing, health and other topics. Between 2005–2007 he was the national coordinator of the ESRC e-Society programme. His current research is on the neighbourhood consequences of the super-rich in London.