Every day, billions of people are unwittingly taking part in what is the largest most comprehensive psychological experiment ever conducted. The old marketing and advertising world using billboards, advertisements and TV commercials to persuade us, has been comprehensively augmented by an entirely new field of "user experience architects" and "online persuasion agents." These forces are given tremendous power from the proliferation of digital technologies. So how do these powerful forces ensure that we fill our online shopping carts to the brim, or stay on websites as long as possible? Or vote for a particular candidate? What Makes You Click examines how these prolific entities collectively and individually use, shape, and manipulate our experiences via an online world, not just when it comes to buying things, but also with regards to our free time and political perspectives. The manipulation has become so good that these powerful controllers, former Google employees among them, are themselves arguing for the introduction of an ethical code. What does it mean when the grand conductors of these huge experiments themselves are asking for their power, influence and possibilities to be restricted?