Hit Makers: Why Things Become Popular

by Derek Thompson

To watch how ideas go from zero to a million, Watts designed a model universe with thousands of people—or nodes, as he calls them—connected to other people. Let’s call it Watts World. In Watts World, each person, or node, has two variables: vulnerability (how likely each person is to adopt a new behavior) and density (how many people are connected to each other). Watts triggered these networks of varying vulnerability and density over and over, millions of times, to watch trends spread to millions of people or, more often, not spread at all. The first thing he realized was that there are Goldilocks zones of vulnerability and density. It’s worthless to advertise to an older person who literally never changes her habits (“low vulnerability”) or to a Siberian hermit (“low density”). But the opposite poles are also problematic. Let’s say you’re equally susceptible to an ad from Bloomingdale’s, the Gap, and every other clothing outlet you see. This makes you a terrible bet for any one brand because you’re constantly changing your mind. A consumer who is hypervulnerable to every influence is no more reliable than a consumer who is impervious to all influence. Watts discovered a peculiar point in his network where cascades were incredibly rare but extremely large. Nine hundred and ninety-nine times out of one thousand in this particular Watts World, nothing would happen. But in that one-in-one-thousand moment, the entire network would light up—a massive global cascade. “Huh, that...