This is kind of the idea of Fullfilment by Amazon (FBA). You send your stuff to Amazon in bulk, they keep it in their warehouse, and when you sell an item, tell

This is kind of the idea of Fullfilment by Amazon (FBA). You send your stuff to Amazon in bulk, they keep it in their warehouse, and when you sell an item, tell them where to deliver it to. You can use it even if you don't sell on Amazon.