There’s a reason why the term used for viral growth is to “land and expand”—to build new networks as well as increasing the density of existing networks. By “landing,” viral growth can start new atomic networks, as a Dropbox invite from an ad agency to their client brings a new company into the collaboration network. Or, when a WhatsApp group chat invite brings onboard a new set of friends who hadn’t previously used the service. But then the product “expands”—increasing the density of a network as all the coworkers in an office ultimately join Dropbox.
