Your Help Needed: Book Trailers

I'm looking for your input again, this time about "trailers" (short preview videos) for books like Resisting Gossip.

+   What makes a great book trailer?

+   What would cause you to watch one from start to finish?

+   What are the most important elements to include and exclude?

+   What are your top turn-offs to book trailers? Why would you close your browser instead of watching it all the way through?

+    What other advice would you give a small budget producer for book trailers?

Thanks, in advance, for your counsel.