The Clue Bit of movie publicity, briefly
The Answer PROMO
The answer "PROMO" fits the clue "Bit of movie publicity, briefly" because it is a common abbreviation for "promotion." In the context of movies, a promo can refer to advertisements or trailers that help generate interest. The word "briefly" suggests that the answer is a short form, which "PROMO" is. Overall, it perfectly captures the idea of a small piece of marketing for a film.