Earlier quoted context omitted.
"with parity in delivery time, product quality, returns experience, etc." How would the user know that? Many sites, including Amazon, make their bones providing decent quality at a lower cost, and then once they build up their market they start reducing the features and raising the costs. Amazon tends to be more expensive nowadays and suffers from product quality issues. It is super easy to use and has a good return…
Still can’t beat the delivery time though. Their logistics network is insane.
I suspect super fast delivery is only a differentiator when all else is equal. At $6+/gal diesel, I'll take the cheaper item delivered by bicycle in a week. (A bit of a joke, but you get the point.)