[candu]

It's a reasonable response: that driver isn't delivering groceries to you, they're delivering to your whole neighborhood. As the density of delivery orders goes up, there's more and more opportunity to batch nearby orders like this.

In addition: if you pre-order a bunch of deliveries, you're giving the delivery service more cash upfront. That usually allows for greater efficiencies in how the cash is spent and/or invested in the business.

Of course, if they never reach the break-even density, the whole thing is doomed to slow failure.