The Four Kinds of Social Capital that Matter When Building Products
Though the term k-factor, a measure of the virality of an application, has waned in popularity since Facebook’s sheep-throwing glory days, the idea of spreading a product through referrals lives on. We all know a good referral mechanism when we see one. Dropbox’s invite-a-friend feature which awards free storage for both the inviter and the invited is the canonical example and resulted in torrid growth for the company. In April 2010, Dropbox users sent 2.8M referral emails. It’s these kinds of referrals, those that align the incentives of both parties and ones that are natural to the product, that seem to work the best.





