In a production environment: Clojure combines all of the resources of the Java/JVM environment with a nicer (in my opinion), dynamic syntax. It also has the best standard library of any language I have worked with, bar none.

From a learning standpoint: Clojure and other functional languages are worth using because they make you approach problems differently, and in doing so you become a better programmer.

Source: used Clojure in production building a real product for ~3 years