Amazon isn't commenting on the project, and it's not clear just how many of these stores will pop up. The Sunnyvale experiment is likely to expand to other areas in Silicon Valley, but there's no certainty that it'll ever rival a big chain like Safeway. However, there's no question that the concept makes a lot of sense for Amazon. It eliminates many of the headaches associated with shipping food directly to your door (how do you deliver a mix of fresh and frozen foods, for example?) while giving you an incentive to skip traditional supermarkets. You'd miss out on the joy of discovering tasty treats at the store, but you also wouldn't have to spend more than a few minutes getting your weekly sustenance.