Lord of the Rings began as a moderate success, garnering mixed reviews but an avid following.  The book took on a unique persona as a catch phrase for the hippie movement of the 60s and 70s with "Frodo Lives" appearing on T-shirts, buttons, graffiti, and even an album.  The saying is linked to the theory that Frodo lives forever after the end of the Lord of the Rings trilogy, though Tolkien himself said Frodo will die (presumably of natural causes).  Another meaning could simply be that Tolkien’s books will be remembered forever.  The phrased gained in popularity as the books did, especially after the releases of paperback editions encouraging the cult following and embracing by the stick-it-to-the man counterculture, transcending geeks to becoming a true pop culture moment.