They are handed out free to mostly stupid teens and adults to prevent more stupid teens and adults, spread of more disease etc. Given to the agency by other private groups, grants etc. Cases of them around, and I usually pick up the older close to expiring ones that are laying around when I'm working on things. Find them under or behind desks etc, dusty from being on the floor for a year, stuff that probably shouldn't be given out for use. Only need a couple per bug out bag, for whatever reason needed.
I think a lot of the teens take them and sell them to friends. LOL. Nifty colors too, yellow, orange, blue, purple, black, I don't think any of them have flavors, I'll have to check.
I found some Really expired ones in my hunting backpack I bought years ago, little on the dry side, but still were usable for hauling water. (I tested one of them, held up just like a new one)
I like the yellow ones.