This book demonstrates how applying behavioural science to commercial problems can effectively help businesses to understand and achieve the best outcomes for their customers. Bringing together theory and practice the author describes how approaches underpinning behavioural science can be adapted to the fast-moving environment of the private sector.  The first part of the book discusses the underlying theory and principles behind behavioural science. It outlines the history of the discipline, explaining how behavioural scientists use theories and models of behaviour, and discussing why behaviour is so hard to predict. It then describes how the theory can be applied to designing products, services and interventions. In Part II Rubinstein uses several key case studies to explore the challenges of integrating behavioural science into established practices, considering how to use behavioural science in multidisciplinary teams and why this might be useful. She addresses concerns about the ethics of using behavioural science in this context before describing the value of applying behavioural science to business and how best to realise its potential. This book is a must-read for both practitioners and academics interested in applying the science of behaviour to real-world challenges.