Design a product recommendation system.

Focus on the core components of a product recommendation system, including data sources, algorithms, and user interface. Discuss the types of data you would collect, such as user behavior, purchase history, and product attributes. Consider different recommendation techniques like collaborative filtering, content-based filtering, and hybrid approaches, and explain why you would choose one over the others for your specific use case. Finally, address how you would measure the success of the system, including key performance indicators (KPIs) and user feedback mechanisms.