Hmm... You know, they could pre-deliver popular items to local BufferBoxes. And then, as they've got those items already in the space, they could let people look at them to help them decide if they want to buy them right there.
Except shipping packaging (even when pared down by Amazon) is rarely designed to show off the object in question and such boxes (unless specifically designed for certain objects) would have quite a bit of wasted space in the storage units.
Further, you're basically operating a vending machine at that point, but with limited inventory, space losses, undesirable packaging and an undesirable location. (low foot traffic)
The obvious improvement is to just make a proper "redbox for things" vending machine, designed around a few optimized packaging dimensions and start leasing more-visible/accessible spaces to host it.
But what is that, if not just a (small) robotic convenience store? If you could pull off such a machine, why not just build a larger version and outright compete with 7-11?
Interesting; I didn't know that. (Or knew and forgot)
I guess that calls for a re-examination of what Amazon/Google's most frequently ordered items even look like and whether there's much/any cross-over between that and what people walk into a 7-11 to buy.
Though the picture immediately suggests that such a kiosk would have to support asynchronous browsing and order compilation. So that one is not stuck behind a person trying to choose between two candy bars and then 3 bags of snack mix and then... Luckily in 2013, most everyone has a reasonably powerful and competent mobile device in their pocket.
A couple Swedish online computer retailers now have storefronts in the countries largest cities where you can opt to pick up your orders to avoid paying the shipping fee (the storefronts have nothing to browse, just a window to pick up/pay for orders), and they do this with the most common stock.
This is how the standard postal service works in Sweden (except you pick up the package from an employee who checks ID instead of an unmanned box), and why I always avoid sites that ship via FedEx/DHL/UPS. It just makes so much more sense.