I disagree. Value isn't always driven just through single-user use cases. If you focused on making "Draw Something" with a strong single-user focus you'd have a

I disagree. Value isn't always driven just through single-user use cases. If you focused on making "Draw Something" with a strong single-user focus you'd have a dud. I would argue that to think of single-user first and then bolt on network effects is the exact problem with most growth-hack thinking. You can't just put lipstick on a pig and hope for virality. It has to be baked in from the beginning. The goal of the infographic was to communicate the core elements of design that foster viral growth. Answering questions like "How does a user's experience get better the more people they're connected to on the service?" is key to designing the UX in a way that benefits the user and drives growth.