Design a system that ingests book reviews from Amazon.com and provides book recommendations on your website.

Focus on outlining the architecture of the system, including how you would gather and process the book reviews from Amazon. Discuss the methods for scraping or using APIs to access the reviews, ensuring you consider compliance with Amazon's terms of service. Detail how you would store the ingested data, emphasizing database choices and data structure for efficient querying. Finally, explain the recommendation algorithm you would implement, whether it’s collaborative filtering, content-based, or a hybrid approach, and how you would evaluate its effectiveness in providing relevant book recommendations to users.