Anyone in sales or marketing, and especially anyone who is trying to build a successful ecommerce site, can learn a lot from Amazon.com. What started as nothing more than a website that sold books, has now grown to be the largest ecommerce site in the world. Since Amazon’s introduction on the web in 1995, many Internet e-commerce sites have patterned their business models and strategies around this one company.

It’s safe to say that Amazon is definitely doing something right. Among many things that Amazon definitely does right, including their large selection, good prices, and amazing customer service, is their recommendation process. They have created an amazing recommendation algorithm that helps them to recommend very relevant products to their online shoppers.

Any time you shop on Amazon, you will receive many different product recommendations. So how does Amazon come up with these recommendations?

Here are 4 ways that Amazon recommends products:

1. Popular Products

When you first go to Amazon’s home page, one of the first things you will see is a section called “What other customers are looking at right now.” This will show you images of several items that other people who are also currently on Amazon’s site are currently viewing. For example, if you go to Amazon’s home page at the time that I am writing this article, you will see product images and links for a Kindle Fire, an Amazon gift card, a pair of headphones, and a backpack.

This feature shows you what other people are viewing on Amazon at the same time that you are on their site. This helps you to see what some of the other popular products are on the site, and what other customers are interested in. This is very helpful for people who are just going to the site to browse around, and to give them ideas of some products they may be interested in.

2. Customers Also Purchased

When you go to a specific product page, you will see at the bottom a few different sections with product images and links. These sections include “customers who bought this item also bought” and “customers who viewed this item also viewed.” This helps shoppers to find other items that are related to the item that they are currently viewing. It takes a history of the items that other customers purchased and viewed while they were viewing or purchasing the item that you are currently viewing. It helps their shoppers to see items that are similar to the item that they are viewing, as well as items that may go well with the item that they are viewing.

Amazon also takes this aspect one step further. They also have a “frequently bought together” section where they have created packages of items that go well together. When you purchase one of these suggested bundles that go well together, they will give you a discount on the bundled items. For example, if you are looking at a stainless steel pot, they have it bundled with a stainless steel ladle and a stainless steel pot in a different size. If you purchase all three items together, you will receive a small discount on those items.

3. Similar Items

The great thing about Amazon is that they work to cater your shopping experience to your individual preferences. So, they keep a history of the items that you’ve viewed in the past, and they work to show you related items that you may be interested in based off of those items. This section is called “related to items you’ve viewed.”

Let’s say the last time you were on Amazon you looked at a red summer dress. The next time you go to Amazon they may show you similar red summer dresses from different designers and in different lengths.

4. Browsing History

Amazon will also keep track of your browsing history and show you items that are related to searches that you’ve done on their site in the past. When you go to their homepage, they have a section called “inspired by your browsing history.” If you’ve recently searched for a digital camera in one of your recent visits to Amazon, the next time you are on their site you may see other digital cameras.