I would imagine the curve of "people buying new bags because they forgot" over time is real real high over the first 6 months, with sharp drop at some point and

I would imagine the curve of "people buying new bags because they forgot" over time is real real high over the first 6 months, with sharp drop at some point and a thin tail in the future. The idea of people frequently forgetting bags and needing to buy one at check-out just doesn't seem to jive with long term reality from what we've seen in other places that have done similar things.