Interesting, I saw this as the opposite. Without the existence of centralized checkouts, retailers can craft totally different experiences for shoppers. It's in their best interests to keep shoppers in stores for longer. A great example is wine tastings at Whole Foods locations - it's clearly a social event within a grocery store.

I'd say there's going to be even _more_ opportunities for social interactions at grocery stores like Amazon Go.

To your point, though, the "marketplace" you're talking about is the ambiguity between the consumer and the worker, aka Marx's point about the commodity fetish. That's something that's existed since the late 1800's, though. I don't think that's going away anytime soon.

Although I can see something similar to a farmer's market run in the same format as Amazon Go. I haven't thought through all the edge cases yet, but it feels like a solvable problem.