It’s been 21 years since the first banner ad appeared on the web. It ran on a site called HotWired.com, the original website of Wired Magazine, and it asked, “Have you ever clicked your mouse right HERE?” Who knew that it was the dawn of a new era not just for advertising, but for all of marketing? In the ensuing years, the technology ecosystem enabling the new ad medium would steadily unfold, while digital devices proliferated and network connectivity became ubiquitous.

Now, many ads are served up by software systems targeting any digital device—from your smartphone and TV today, to the dashboard of your car and the thermostat in your home tomorrow. Soon, every display will be an addressable medium—that is, each will be individually targetable by device and, in many cases, down to a specific user; and interactive displays will not only deliver ad messages but also track consumer response.  What does the new world of marketing where digital technology automates buying and targeting look like?