Earlier quoted context omitted.
Wal Mart became a giant by operating on low margins...scaling, then using scale for purchasing leverage... I wouldn't assume that Google is paying the same price that ordinary customers are in the retail settings Google order fillers pick from.. Likely rates were negotiated before launch...
Yeah but groceries are a very thin margin business half percent to two percent profits. There isn't a lot of room for negotiating great prices.
Including groceries makes the existing, more general Google Express shopping service more valuable, and negates an advantage that Amazon's competing service, which already has grocery delivery, has over Google's service.
Analyzing the grocery delivery bit as if it were a standalone business is an error.