SnapChat's growth has been off the charts. They now have more "snaps" daily than Facebook photo updates. While there is no single formula for rapid growth they were able to grow so quickly because: 1. Mobile First- They focused on mobile first in contract to Facebook and other web first brands. 2. Youth- The appeal of SnapChat is targeted at the most active and prolific smart phone users. 3. Controversy- Controversy builds buzz and fosters conversation and sharing. 4. Network Effects- SnapChat increases in value to the user as more of their known connections sign up. This incentivizes the user to spread their uses virally.