amazon collects massive amounts of data about how, when, why, where, and what people buy, and then analyzes those data to better serve its customers. this activity refers to

This activity refers to data mining (using big data analytics for marketing decision-making). In a typical business/marketing context, the phrase:

“Amazon collects massive amounts of data about how, when, why, where, and what people buy, and then analyzes those data to better serve its customers”

is describing how a company uses data mining and big data analytics to discover patterns in customer behavior and then apply those insights to improve recommendations, personalization, pricing, and service.