If Amazon sets up a physical business in any given state, they have to start collecting sales tax on all their sales to that state. So "cost effective" for Ama

If Amazon sets up a physical business in any given state, they have to start collecting sales tax on all their sales to that state. So "cost effective" for Amazon Fresh means not just cost effective in isolation, but also accounting for the cost in infrastructure, lost sales, etc. that comes with collecting sales tax. That's one of probably a dozen reasons why what works (or doesn't) for Amazon might be different for Instacart.