If you buy a lot of items on Amazon.com, you may want to check for things that are delivered to you that you haven't purchased yet.

The online retailer claims it knows its customers so well, it can ship what you want before you even order it.

Last month, Amazon.com received a patent for what it calls Anticipatory Shopping. The company says it may ship products based on customers' previous orders and shopping habits, such as searches, wish lists and shopping cart contents.