I'm very doubtful of drone delivery until battery tech advances at least 10x.
In dense, built-up areas there is no space to land. You can't fly between buildings and land on a sidewalk in Manhattan, and where would you leave the package there?
In rural and suburban areas, where houses have backyards, the flight range starts to be a problem. Amazon isn't going to build a full warehouse every 5-10km, even "drone depots" seem doubtful with that density. With "drone depots" instead of proper warehouses, the packages would still have to be trucked in, so 1-2 day delivery instead of 1-2 hour delivery, and the only motivation would be cost saving over traditional mail carriers.
Perhaps if batteries become a lot more capable, then having drone depots every 20-50km in suburbia might end up profitable over paying for mail.
While I agree with you that space to land is an issue, in terms of trucking in packages to smaller depots, Amazon already does this in some markets like the UK, where it is investing heavily in regional depots and doing "first level" delivery from their large warehouses to the smaller depots themselves.
Here it depends on quite high population density in the regions they are putting depots, which still has the landing space issue, but e.g. their two London depots puts them within possible delivery distance of several million people with front or back gardens. A large proportion of the ones who don't have private gardens have communal spaces.
The bigger problem than where to land for me would be how to handle "handover" to their customer without ending up leaving packages in plain sight in areas where it's easy for someone to snatch it.
In dense, built-up areas there is no space to land. You can't fly between buildings and land on a sidewalk in Manhattan, and where would you leave the package there?
In rural and suburban areas, where houses have backyards, the flight range starts to be a problem. Amazon isn't going to build a full warehouse every 5-10km, even "drone depots" seem doubtful with that density. With "drone depots" instead of proper warehouses, the packages would still have to be trucked in, so 1-2 day delivery instead of 1-2 hour delivery, and the only motivation would be cost saving over traditional mail carriers.
Perhaps if batteries become a lot more capable, then having drone depots every 20-50km in suburbia might end up profitable over paying for mail.