To hasten the app’s viral growth, the team, led by Zack Onisko, devised a brilliant hack of Facebook’s invite system to get more users to share the app with their Facebook friends. At the time, Facebook allowed users who installed a new app to invite other friends to use it, too (and, in fact, many of the apps that grew virally on Facebook took advantage of this mechanism, such as the wildly popular game Farmville).
