If shipment cost is reasonably low, just deliver predetermined items (e.g. those recommended by Amazon) to customers, have them pay for what they consumed and r

If shipment cost is reasonably low, just deliver predetermined items (e.g. those recommended by Amazon) to customers, have them pay for what they consumed and return the rest. Or, if storage cost at customers is low and items do not perish, leave the items they didn't consume at their site. Later they may find them useful and pay for them. This is actually the model employed by some of medical drug resellers in Japan.