Direct marketing theory maintains that before the average person reads a sales letter, he or she takes a second or two to scan the page, looking for highlights or clues to determine whether the letter merits the time to read at greater length.

If you design your letter to take up as little space as possible (adhering to an arbitrary one-page limit, for example), almost inevitably the result is a letter that looks crowded, with large, unwieldy paragraphs that are intimidating to look at, difficult to read, and impossible to scan.

In fact, compressing your letter onto one page is often the worst thing you can do. Instead, expand your letter by breaking up the text as much as possible. Techniques like bullets and sub-heads (short, highlighted phrases between paragraphs) may extend the length of your letter onto a second page, but they actually make the letter easier to read (and therefore, more inviting) by dividing it into smaller, more digestible pieces.

Sub-heads have another benefit also. Used to summarize key selling points, they serve as "teasers" - devices designed to grab the attention of the reader and motivate him or her to read further. To be most effective, each sub-head should deliver a concise, compelling benefit. For example: