I have no idea either, but it has happened three times now. They are one street away, then stay there for an hour plus. Then it's suddenly delivered, but there is no package. I only order stuff which will arrive on days I am in. These three times, I was in, the doorbell didn't ring, no one showed up on camera, but tracking said it was delivered to my address and handed to the resident! Sometimes things are left on doorstep as I don't get to the door fast enough, I know they are on a tight time frame, and I wouldn't like their job, but these three times, nothing had been left/delivered. I imagine just driving up a street, pausing outside a property would show up in the tracking and could look like delivered. It's not like they ask for a signature or a photo of person accepting it. Amazon refunded/replaced each item, and I did complain and suggest they looked into it, but what do they care?