Virality is not a feature you can add after designing your product. It is neither adding “Like” or “Tweet this button” nor vigorously integrating all the Facebook Social Graph API features. It is instead something inherently built into your product.

When turning an initial app idea into a product concept, ask yourself:

  1. Can my product idea ever be viral, or are there certain limiting beliefs preventing people from sharing their experience? Platforms like dating services can even offer hugely different subscription fees per acquisition channel at the same time, because people rarely talk about this in public or recommend a specific service to friends and coworkers.
  2. Is a viral engine of growth really what works best, or might I be better off focusing on paid marketing? In e-commerce, companies can measure and thus optimize their conversion funnels, from search intent to purchase, on a cost per order basis. As long as their bid for an ad is always lower than the customer lifetime value minus all costs of service delivery, the more they purchase, the more they grow.

If you have figured out that viral is the way to go, stick with these questions:

  1. Is my product really worth much more when users bring their friends — probably to such an extent that it does not work without them? Facebook’s entire business model relies on users generating content and convincing their friends to join and then stay for easy status updates, picture sharing, organization of events and group communication.
  2. What gets a user made (feeling like a hero) or paid (in respect or money) when inviting others, and with which overall product and feature design can I achieve that best? Letting friends know about free, easy and reliable online backup solutions makes early adopters feel special. In addition to that, Dropbox grants additional storage for every successful referral as soon as friends have signed up and installed Dropbox on one of their devices.