Poptropica is an adventure platforming MMO aimed at kids from 6 to 15 years old. With 500,000,000 characters created and 8,000,000 monthly users, Poptropica could rest on its laurels. But after five years of strong growth, its developers decided to expand the multiplayer component by adding social gameplay. They faced a number of challenges, from upholding COPPA compliance and providing a safe environment for their players, to maintaining a focus on strong narrative and simple, intuitive gameplay. The talk will cover the specifics of the development process for this project, and discuss its consequences and lessons.