I will say that at the HS my kids attended (3 AF brats...different HS in different states), somebody always came out to present. There is a big reason why they do this...free advertisement.
I recall our DSs very clearly from a parent's perspective. It was an AFROTC PMS from UNCCH that did it (UNCCH was @50 miles from the HS). They spoke about that they not only were paying 72K in tuition to any college of his choice, but it also included a monthly stipend totaling over 17K (back when 400's got $550/mo) and the book allowance. They then went onto say he would be guaranteed a job upon graduation. He discussed our DS's stats (SAT/ACT, cgpa) and compared them to the avg stats for a type 2, but threw in the avg stats for a type 7 recipient too.
As this was occurring DS had not been called up yet, thus parents sitting around us in the audience did not know who the recipient was. Behind Bullet and I we could hear people talking about it, and parents saying things like next year when their 2nd,3rd, 4th child, etc. starts the process they need to look into this. They had no idea that it was our DS until his name was announced and saw Bullet and I kiss each other in pride. Immediately afterwards people were tapping us on our shoulders and congratulating us. After the awards ceremony the PMS was swamped by parents wanting to know more information, no exaggeration, but it was probably a dozen parents.
Thus, you see it is what someone would call good business sense, not out of kindness, but the best bang for their buck! No tv adverts, no website costs, just good old word of mouth. Couldn't get any cheaper...even the PMS at an AFROTC det. knows that this is part of their duties...there is no such thing as overtime pay in the military.
They had a captured targeted audience...HS parents, with kids that are receiving academic/merit scholarships and probably had more kids that would be looking into scholarships. IF only 5 parents at that ceremony starts to investigate ROTC, than it 5 more kids in the pool. Multiply that nationally and they now have spread the word that this program exists, just as fast as the internet. Parents talk to their siblings, friends and neighbors about the cost of college and how they can pay for their child's dream college. 4 years of ADAF, guaranteed paycheck is something that they can bite off on knowing that they will get spending money on the AF dime, and at least for the AF, tuition is covered, leaving them only R & B.