Facebook virals can definitely work. I know this because I'm the PM for an app that has grown virally 1.75% a day (on average) over the last eight months. Peop

Facebook virals can definitely work. I know this because I'm the PM for an app that has grown virally 1.75% a day (on average) over the last eight months. People see a disconnect because they think that the mere presence of like widgets or some open graph actions will cause viral growth, and then when it doesn't happen they get frustrated. What works for virals isn't obvious - the app has two FTEs working on virals and the results are consistently counterintuitive, but the nice thing is that what works does seem to be consistant across apps.