The ultrafast vision is to replace the local grocery store the way Uber disrupted car ownership. By turning groceries into something summoned at the touch of a button rather than something planned and scheduled, ultrafast services want to change how we shop entirely.

It's possible that a delivery co-op for restaurants would be cheaper than them using delivery services. They could all pool their resources and hire a single delivery driver who does everyone's orders.

The strategy is largely out of the same playbook as other on-demand apps—capture customers, consolidate control over a high-frequency behavior, expand and cross-sell to other higher-margin categories. But their challenges are significant as well, from spoilage rates on grocery to hard-to-predict inventory requirements and building relationships wit... See more