I get your point, but with a kiosk they could dynamically give special deals, like "add fries for $0.18" if it is profitable for them at that moment (maybe they

I get your point, but with a kiosk they could dynamically give special deals, like "add fries for $0.18" if it is profitable for them at that moment (maybe they are about to toss the batch of fries). Honestly I wouldn't consider McD's cashiers to be good salesmen.