[cstreit]

They used very sophisticated algorithms to predict what people will order where and when... Inventory is spread out according to this... If they know that someone is likely going to order toothpaste in an area, they will ensure it is close.

Add to that extremely efficient large warehouses and lots of smaller micro-warehouses that are replenished frequently and you have their success recipe.

Much like google pretty much knows what you're about to search for...