Just think about someone needs to stroll around Walmart and find all these 4000 items each month chosen meticulously, buy them, store them, package them and shi

Just think about someone needs to stroll around Walmart and find all these 4000 items each month chosen meticulously, buy them, store them, package them and ship them. Then there is a classic and dreaded inventory problem. The items you bought from Walmart has no guarantee that they will get sold by same day, week or even a month. It's not hard to imagine that you will need 2X inventory and many of these items may go unsold in long tail easily wiping out significant profits.