AWS and advertising are where their margin and profit centers are.
In terms of retail support action - Costco's stock is one of the few large companies that hasn't cratered. It's not much lower than its average for the year, whereas most everything else has been hammered.
You could double Amazon's retail sales in the US and it will get you a few extra billion dollars in profit. The problem is retail makes up a very modest share of their overall profitability. So it won't move the needle much on a $840 billion market cap. It works for Costco because essentially all of their market cap is based on retail sales and the demand surge they're seeing. So you get a direct IV line between the crazy panic buying and the COST stock. Although, if there are supply problems coming up next, be careful holding COST as well.