There's some who aren't eligible for the pharmacy discounts. Those living in New Jersey, New York and Arkansas (however, I can't see stores in those states being able to accept these coupons).
And those whose insurance is partially funded by the US government. At first, it was thought to be those on Medicare. However, it turned out that it meant all types of insurance partially funded by the US government. Including Armed Forces and Federal Employee insurance.
Several years ago, Walgreens was fined several million dollars for giving gift cards to federal employees for switching their prescriptions over to them.
Hurts me big time. I'm a Federal Employee with a number of scripts every month. That extra 5% would come in handy.
Anyway, I'm thinking it's feds or retired on Medicare that could be buying up these discounts on eBay.