The document discusses how big data is used in ecommerce. It describes the four V's of big data (volume, velocity, variety, and veracity) and the value chain of big data including data origins, integration, analytics, and applications. Data sources include internal transactional data and external sources like Google Analytics. Analytics are used to measure marketing activities and key metrics like customer acquisition cost and lifetime value. Customer segmentation, product associations, personalization, dynamic pricing, and delivering customized content are also discussed.