The power of many sales efforts lies in the skill to write a great sales letter. You'll find the underlying magic of a strong sales letter in many different places—including emails and web pages, as well as actual direct mail packages.
At its core, a direct sales letter is a selling machine. It is crafted in such a way as to grab and hold a reader's attention. You want to engage that reader and pull him or her in to your story. In other words, a boring sales letter won't get you anywhere.