[DrScump]

  the grocery picker... makes a bunch of deliveries in one trip

That would mean that the customer who is the farthest along the delivery route had better not bought any perishables like ice cream or rotisserie chicken.

In actual practice, that model doesn't work for anything but dry goods... which means somebody is making an additional trip yet for temperature-critical perishables.

Webvan crashed and burned partly because they failed to think out the "edge cases".

[lsc]

>In actual practice, that model doesn't work for anything but dry goods... which means somebody is making an additional trip yet for temperature-critical perishables.

Safeway uses a refrigerated van

Amazon fresh packs produce with ice packs in a bubble wrap cooler inside a paper bag; frozen things get dry ice; I've ordered ice cream 'unattented delivery' (where they leave it outside my door) and it can go hours without harm.

(Amazon fresh uses a whole lot of packing material, which is another problem... but point being, they've solved the 'food melts on the way to your house' problem)