>If Marty is roaming the aisles at a reasonable speed (i.e. not so fast as to endanger shoppers!), there's still a substantial chance Still substantial but les

>If Marty is roaming the aisles at a reasonable speed (i.e. not so fast as to endanger shoppers!), there's still a substantial chance Still substantial but less than without it. Most of the restocking and cleaning happens when the store is closed. Customers don't want to have people getting in their way stocking shelves and you don't want to be mopping floors (other than cleaning up spills) when customers are walking down them.