One of the key and most-known features of Amazon is the intelligent product recommendations named "Customers Who Bought This Item Also Bought".
The Also Bought app brings this feature into Shopify in the most convenient way: you can have Amazon-like recommendations in your store in seconds with zero configuration.
Also Bought analyses the previous purchases in your store database through data mining algorithms and produces a memory graph with the recommendation information.
When a customer visits a product page, a list of the products usually bought together is displayed.
These are true recommendations, much better than selecting related products manually or by other criteria: customers are more likely to purchase products that other customers bought in the same situation.