The sweeping changes that the Internet of Things (IoT) - digitising the physical world - can bring to companies, consumers and cities have thrown up myriad possibilities, inspiring a surge of innovation and enthusiasm. A report by the McKinsey Global Institute estimates the economic impact of the IoT could be $3.9 trillion to $11.1 trillion a year by 2025 - from improvements in productivity and asset utilisation as well as economic gains of reduced disease and accidents, among others. Here is a snapshot of the report: