I don't know if trailers work in terms of sales, since I have them and I don't sell well. It depends on the quality of the trailers and, most importantly, how popular the sites are that you get exposure for them on are.
Trailers are not terribly hard to do, though, and they make for something different to display on your blog, FB, etc. You can also add them to your Amazon page.
In my opinion, they are good things, but I am unsure if they result in more sales or not. I've seen awful trailers that did more harm than good, but the acceptable ones I see no harm in.
(As a consumer, I wouldn't be influenced by a trailer I don't think, though.)
Trailers are not terribly hard to do, though, and they make for something different to display on your blog, FB, etc. You can also add them to your Amazon page.
In my opinion, they are good things, but I am unsure if they result in more sales or not. I've seen awful trailers that did more harm than good, but the acceptable ones I see no harm in.
(As a consumer, I wouldn't be influenced by a trailer I don't think, though.)