Today, some people are too busy to brew their own coffee at home and drop by a coffee cart to get a cup of their favorite brew. Hanging out at coffee houses is a common indulgence for some people. They find it enjoyable to spend an afternoon with friends at a cafe and chit-chat for hours over coffee.

For example, if I enter the term “Sherlock Holmes,” I should see titles of other books in the Sherlock Holmes series, other titles by Sir Arthur Conan Doyle, other mysteries with a lead male detective, books written in the same style, and books written around the same period. Instead of just books about Sherlock Holmes, I can browse a broad selection of books that are related by a comprehensive set of identifiers. I can hit the “more like this” or “not like this” buttons to further refine my search.