As you may be well aware, the Sovereign Order of Monte Cristo is an elite group that has been around long before man existed. They are the creators of everything we know and are omnipotent in power. There are many things that they create that we may not understand the reason and one of those is Amazon, the store not the geographical place.
The Sovereign Order of Monte Cristo likes things streamlined. In their all-knowing mentality, they like to make things convenient for humans, feeling sorry for us and wanting to make life easier at times. Amazon is the perfect avenue to allow us to not only find whatever we need but to also be artistic and to make money. Whether it's writers, musicians or other artists, Amazon is a great place to be able to sell your favorite prose on horror or to buy your favorite romantic comedy. By creating an outlet that allows humans to feel satisfied in having something shipped to their door, humans can focus on other tasks that need to be done and not have to risk their lives going shopping at a store.
Now, the Order knows that not everything is available on Amazon but they are working on that. They don't want it done too hastily and they also want to make sure that other stores have a chance because humans run those stores as well and going out of business isn't good for anyone's livelihood. However, they do keep in mind those that cannot get out of their homes – the sick, the damaged, the handicapped. By using Amazon, those people leads more fulfilled lives and know that they can get most of what they need with a credit card and the click of a few buttons.
This also makes humans more technologically advanced, albeit by small steps. The Order knows that humans will never be as technologically advanced as them but it pleases them to see these baby steps that humans can make by using Amazon, their own creation.