retail news in context, analysis with attitude

On the subject of e-commerce economics, one MNB reader wrote:

My guess is that picking customer orders from a warehouse, even using the Ocado system, is at best significantly less profitable than sales from typical brick and mortar retail locations.  So without physical stores where they can rob Peter (customers who do their own shopping and delivery) to pay Paul (the extra costs of online ordering and delivery) online shopping is always going to be less profitable than in store sales.  

Isn't it also possible that running a warehouse/dark store actually eliminates a lot of the costs of a physical store that has to be maximized for customer contact?

There's a phrase often used:  With all things being equal …

I think it is important to realize that all things don't have to be equal.