Hit Makers: Why Things Become Popular

by Derek Thompson

It’s become fashionable to talk about ideas as if they were diseases. Some pop songs are infectious, and some products are contagious. Advertisers and producers have developed a theory of “viral” marketing, which assumes that simple word of mouth can easily take a small idea and turn it into a phenomenon. This has fed a popular conception of buzz that says that companies don’t need sophisticated distribution strategies for their product to go big. If they make something that is inherently infectious, they can sit back and wait for it to explode like a virus: In epidemiology, “viral” has a specific meaning. It refers to a disease that infects more than one person before it dies or the host does. Such a disease has the potential to spread exponentially. One person infects two. Two infect four. Four infect eight. And before long, it’s a pandemic. Do ideas ever go viral in that way? For a long time, nobody could be sure. It’s difficult to precisely track word-of-mouth buzz or the spread of a fashion (like skinny jeans) or an idea (like universal suffrage) from person to person. So, by degrees, “That thing went viral” has became a fancy way of saying, “That thing got big really quickly, and we’re not sure how.” But there is a place where ideas leave an information trail: on the Internet. When I post an article on Twitter, it is shared and reshared, and each step of this cascade is traceable. Scientists can follow the trail of e-mails or Facebook posts as they move around the wo...