[And, it takes me half hour to an hour to do my shopping, and that's knowing what I want to buy in advance, knowing the store. There is not much room for profit in this scenario, except charging value added rather than flat fee. I mean they are partnering with local grocers rather than automating food stores]
If anyone has the reach and network it'd be the USPS (although their fleet would have to be modified to carry perishable goods).
Seriously, they've been hemorrhaging money, why doesn't or hasn't the USPS looked into the growing same-day delivery market (beside their Amazon deals). Are their unions holding them back, because if they are, it's shortsighted. They should have logistics down to a science.