In short submit lots of accurate filmography items! Filmography refers to cast and crew credits, please see http://www.imdb.com/badge/
"Gold, Silver and Bronze classifications with levels ranging from 1 to over 1 million active contributions. This badge consists of the lifetime count of all cast, major and minor crew submissions, corrections and deletions. Gold level is reserved for roughly the top 1-2% of all filmo contributors."
