When librarians use, create, or teach others to create booktrailers... they are marketing books, authors, and reading. This new Librarian-promoted (and student-promoted) trend is a good thing. It is NOT something librarians and other educators are taught in college or grad school. It is a win-win-win strategy. Librarians need to develop a tag line such as "powered by the XYZ library". Next step: Figure out how to measure results.
The June 2010 annual American Library Association conference included a panel program organized by the YALSA (Young Adult Library Services) Teens and Technology Interest Group on creating booktrailers. Booktrailers are promotional music videos similar to movie trailers. "ALA10: Lights! Camera! Booktrailers!" included an author, a book publisher, school and public librarians who shared how they create or teach booktrailers.
Librarians interest young people in reading books by teaching them how to create booktrailers. After all, you can't create a video about a book if you haven't read it! Vallencia District Librarian Joy Millam's "Booktalks and More" wiki includes a how-to on creating book trailers and a growing list of booktrailer student-created examples.
Georgia Teacher Librarian and blogger (The Unquiet Librarian) Buffy Hamilton spoke about how librarians can use existing booktrailers to teach and engage students.