While a vacuum was the item suggested to me, I think other items make more sense. Many of these items already are commonly rented, even with the large hassles involved in renting them such as driving to rental stores and doing paperwork.

The deliverbot is going to be a lightweight electric vehicle and thus lower in energy costs. And indeed energy of manufacture (and shipping all the way from China) is going to be much larger in many cases.

I also expect more devices of the future will know when they break, so human inspection will be less necessary. If something arrives broken, just call and another one will be there in 10 minutes. You are the human inspector. If you break it as soon as you get it you might blame the other guy but this will be rare. Insurance covers this.

But the big thing is convenience. Going to the basement of an appartment building for a vacuum is not convenient. A robot at the door or in your garage is.

I'm not sure this will pan out, but many people rail at our consumer culture, where everybody has their own private stuff when the stuff could possibly be easily and efficiently shared with deliverbots. With small light items like DVDs, we already have this with netflix. Perhaps it can happen with more than DVDs.