Incidentally, the soda (gas-injected water plus syrup) is so cheap this [a real boy really named Peyton coming in and filling his bin for the fill-your-own-cup-special] would be better indulged and tolerated as a photo op and free advertising. When you get a fast food cup and free refills, the cup is literally more expensive than the soda + ice that goes into it. It's nearly 100% profit.
ETA The same is true for people who eat too much at AYKE buffets. Take a picture of the dude, and have him sign the guest book and put him up on the wall of eating champions. The loss from one over-eating dude is going to be made up by the draw that yes, we mean all you can eat, and all he ate. Managers who throw big eaters out are just short-sighted and failing to do the math.