Do book-trailer videos work?

 That's the question. Do book-trailer videos work? How, and where, do you post these videos in order to spread the message out to the widest range of potential readers? How long should a video be? What sites are out there expressly designed to help authors who delve into this medium?

I haven't a fracking' clue.

To say I am taking baby-steps in exploring this venue would be mind-numbing understatement. But I'm looking into it.

So far, I've had three videos created for me. Two .30-second ones, and one a little over 1-minute in duration. All three, I think, came out pretty good looking. I'm going to share with you the longer of the three. It is your task (if you so choose to take the mission, Mr. Phelps)  to tell me if it feels long enough, or if it is too short. Should I stick with just music as a background flashing over text? Or should I find a narrator to read voice it appropriately?

Here goes. The ad;

If you want to see the .30-second ads, go to the right and click on the book face for Evil Arises, or the one for Murder Is Our Business. On the Amazon page, scroll down until you see the video and hit that.