What is the basis of Amazon's recommendation system and "predictive trial delivery" patent?

Big data mining and machine learning algorithms.

1. The recommendation system uses massive data mining to provide users with personalized decision support and information services efficiently, and improve user experience and business benefits;

2. "Predicting trial delivery" is a service that uses machine learning algorithm to predict the probability of consumers buying goods, transports the goods to the nearest warehouse in advance, and delivers them quickly once the consumers place an order.