It wouldn't surprise me to see it become popular among other lines.
Yet another scenario - what is a typical response to having to pay for something that was previously "free"? Get as much as you can for the money. I can see this actually increasing waste. Before the fee someone might have ordered one sandwich and some chips. Now they might order several items. After all, the fee is per order and not per item or per person.
Did they really think this through before implementing it?