If the last few decades have been about big digital forces — the Internet, social media — he notes that the future will be about applying all of that in the real world. "Wondrous as the Web is," he writes, "it doesn’t compare to the real world. Not in economic size (online commerce is less than 10 percent of all sales) and not in its place in our lives. The digital revolution has been largely limited to screens." But, he adds, the salient fact remains that "we live in homes, drive in cars, and work in offices." And it is that physical part of the economy that is undergoing the biggest and most fundamental change.