...Even though they're not actually called "blurbs." ;)
I hang out a lot of writing and self-publishing forums, and fellow authors are often stumped by how to write a good product description for their books...or query letters if they're pursuing agents. It seems like a really tough proposition on the surface, but these two videos show how to distill your book down to the features that are guaranteed to be compelling to your target audience. And the trick is, ALL books have the same compelling features, no matter what the genre!