To be sure you get your overnight or two day shipping, shoppers must pay the fee charged for one day shipping if they do not have a Poat Office box at their home.
We're rural and will never have a PO Box on the road. With Amazon using 'Smart Post', their hand off system to the PO, we are assured confusion and hit and miss deliveries, depending if they punt the package to the PO, which has become increasingly common. That's the service with the annual Prime Membership fee.
The Prime Membership is almost useless for us rural folk.