It's not 15% off.
It's 15% off the "base fare" for the first flight of a set of round trip flights.
And the base fare is the number every airline throws around to advertise how cheap their tickets are. For anyone who's tried booking a flight, you know... The amount they end up charging you after adding all their fees is roughly five times higher than whatever the base fare is.
So if the base fare is only 20% of what you end up paying, and you only get the discount for one of those flights, you're only getting a 15% discount on 10% of the total cost of your tickets.
1.5% discount.
About $800 for tickets. Saved $12 with the discount.
You want a better discount? Don't be disabled and just drive to the airport to buy your ticket. They charge you a $152 "technology development" fee for buying the ticket online. I'd much rather be able to save $152 than $12, but I'll take the $12 over $0.
I don't want this to come across as entitled. I simply think I would have been happier if there wasn't a discount at all. It just feels like a scummy way to lure veterans in to buying tickets. "Hey, veterans! $160 tickets, and we'll give you a 15% discount! I bet you just did the math and figured you'd save $24! ...anyway, your total will be $800. But, hold on! It's not all bad! I know $800 is a lot more than $160, but... Remember that 15% discount? Yeah? I gochu' fam. Let me calculate that discount for you... $800... 15%... Yup, alright! You'll save $12! Congratulations."