Rich snippets provide additional structured data in search engine result pages (SERPs) for certain content types like reviews, people, products, organizations, and events. This can increase click-through rates (CTRs) for sites implementing rich snippets. The document provides examples of how rich snippets increased CTRs for product and blog search results. It also outlines how to implement rich snippets on a Drupal site using the RDF Extensions and Google Rich Snippets modules to add structured data fields and predicates for content types.