That's really the issue I raised above.
There is no question that younger people live and die by their phone and social media. But for the most part that use is user search driven and user selected "following" links rather than push advertising coming from a content provider. If they are like me - and I'm often accused of acting like an 18 year old - then the little bit of push advertising that comes through to me is quickly ignored as I swipe on to the next thing. The question becomes one of how effective is that advertisement in making young people aware that there is an opportunity that they should look into further?
My guess is that personal contacts - whether a family member, a friend whose joined up, or recruiters at job fairs - are the most effective initial contacts that lead to further searches and inquiries either on phones or home or school computers.
Presumably - if DND recruiting has any clues at all - then DND is tracking how applicants are brought to the recruiters' doors and doubling gown on success. They clearly have to be on social media - no question - but how do they get folks to take notice of that presence in the first place.
That's where I made the tongue in cheek comment about great honking billboards across the street from a school's entrance where they see that "first contact" over and over again to the point where they follow up on other media.