A typical Amazon, FedEx or UPS truck does around 150 to 200 stops a day delivering upwards of 250 packages for suburban residential delivery, and this is performed by one employee and can be done in nearly all weather conditions.
If you stop to consider, not only how many aircraft it would take to perform that number of individual sorties in the same time frame (assuming weather was not an issue), but also how many more employee's (the real cost) would need to be involved to carry out those missions, it becomes obvious that the decision to deliver anything by a UAV is not one based on economics.
Add to this; of everything sold by Amazon, what percentage fits within the weight and size parameters and it really can only be a very small fraction of items. I think they are doing it because they can and it's a gimmick/publicity stunt at the moment but maybe it is also getting their foot in the door for something down the road.
If you stop to consider, not only how many aircraft it would take to perform that number of individual sorties in the same time frame (assuming weather was not an issue), but also how many more employee's (the real cost) would need to be involved to carry out those missions, it becomes obvious that the decision to deliver anything by a UAV is not one based on economics.
Add to this; of everything sold by Amazon, what percentage fits within the weight and size parameters and it really can only be a very small fraction of items. I think they are doing it because they can and it's a gimmick/publicity stunt at the moment but maybe it is also getting their foot in the door for something down the road.