The e-commerce giant has launched a new feature on its app called "Add to Delivery," a button that allows customers to add additional items to a delivery for an order that has already been placed.

You can easily pre-order items on Amazon, like video games, and order not-yet-released items in advance.

In an announcement this week, Amazon introduced a new feature called Add to Delivery. Instead of placing a whole new order when you want to order something else, the company explains, you can now use ...