Let's provide a webinar for and encourage units to produce unit Facebook groups for their members. This will help them in communications, but more importantly, can be used as a recruitment tool.
The unit can create an "event" for their fall sign-up and have all of the parents/youth invite other parents/youth who are on Facebook. Then, for subsequent pack/troop events, the parents/youth can again invite friends to activities.
The unit can also collect photos and videos from all members. This will allow the public to see just what their unit is doing and may encourage others to join.
I know not all parents of this age are currently on Facebook, but the Facebook generation knocking at the door.