Amazon.com, Inc. was founded by Jeff Bezos in 1994, and is currently believed to be the largest Internet-based retailer in the United States.

Being one of the trend-starters in online shopping, Amazon also has many interesting patents protecting its key features - such as:
Methods and system of obtaining consumer reviews
Search query autocompletion
and so on.Taking a look at the oldest filing from Amazon.Com, Inc
Amazon's first patent filing covers secure communication of credit card data on a non-secure network. The patent, US5727163A, titled '

Interesting to see that the initial focus was on providing a safe, secure transaction possibility in the face of the shortcomings of the new internet era.
Its photo patent created some stir in the past, when it was granted a patent on the most basic way to photograph on a white background (Read in detail, here, & here).
Looking at its focus on protecting its intellectual property, it is no doubt that it will stay as the largest online shopping destination in the future.