When the 1st Facebook API was released, I helped build the largest application called SuperWall. The way to increase virality and activity on the wall, was to allow a copy paste virus to perpetuate throughout the network. The DAU with this virus that "Zuckerberg is going to delete your account if you do not log in" kept DAU and virial growth at peak levels.

Facebook could do this too and get the same results. More DAU more money.