When you write a booth sales letter, what action do you want the exhibitor to take? Read a prospectus for a new show? Consider buying more space? Or simply give you a few minutes to make your best pitch when you call?

To convince your reader to take action, a sales letter must be informative, persuasive, well-reasoned and expertly constructed. Writing a letter that works comes with practice. It takes sales savvy, a crafter's skill and an artist's flourish to get your message across.

Here are some tips and techniques that will help you create sales letters that work hard to motivate your prospects. Taking these four steps will get you started:

1. Define your objective
2. Know the facts
3. Select the appeal
4. Arrange your arguments

1. Define your objective
Whether you want to give an overview of your show's benefits, draw attention to new attendee research, or flesh out one sales point that pushes your prospect's hot button, your letter should have a well-defined objective. Once you decide what it is, stick with it and don't wander.

Abraham Lincoln was once asked how long a man's legs should be. He replied, "Long enough to reach the ground." Your letter should be long enough to achieve your objective and no longer.

2. Know the facts
When you sit down to write the letter, have the facts at hand. What data do you need to back up your sales points? Use as few numbers as possible but as many as necessary. Many salespeople cram too many factoids into their letters and bore their readers, who quickly lose interest and stop reading.

Look at the notes you've made during your information-gathering calls to get a feel for the language your clients use. By using the right jargon and buzz words, you establish credibility, grab your reader's attention and establish rapport.

3. Select the appeal
What motivates the exhibitor? If he or she is introducing a new product, then you want to point out why your attendees are highly qualified prospects. Select the appeal to which your prospect is most vulnerable and make your arguments accordingly.

4. Arrange your arguments
Clear organization helps the reader focus on your message. Some might advise you to outline your letter before you begin. I find it helpful to do an outline after it is written. This helps you analyze your logic and reveals gaps or flaws in the letter.

Try underlining the key words. Where do they appear? Are they hidden after long, empty phrases? Move your most powerful words to the beginning of the letter, the beginning of paragraphs and the beginning of sentences. Make it easy for your reader to find the major points or risk losing his or her attention.

Structured to sell
The structure of your letter is like the structure of a sales call. When you talk to prospects, you want to capture their attention, build interest and desire, and motivate them to take action. In the same way, your letter must lead the reader all the way to its closing, or you've lost your sales opportunity.

From paragraph to paragraph, you must take your prospect through a series of changes in attitude, to a point where he or she is ready to act. At first your reader may be politely indifferent -- controlled by reason, well-versed in the counterpoints to your points, and possibly even defensive against high-pressure sales techniques. If you try to persuade your reader too soon, he or she may get irritated and simply toss the letter in the wastebasket.

The best defense against a negative reaction is a letter that leads your prospect from point to point and presents the information in an original way, casting new light on the subject. If you can change your reader's perspective, then you're on your way to creating desire, overcoming indifference or suspicion and eliminating objections.

Star, chain and hook
L. E. Frailey, author of the Handbook of Business Letters, recommends a simple formula for structuring a sales letter. It's called the star, chain and hook method. The star is the attention getter; the chain, the sales appeals and benefits; and the hook, the call to action.

Make your prospect the star of your letter by personalizing the opening sentences. Show that you are interested in what he or she wants by referring to something your reader said during your last conversation. Mention names of people in the company, and use the name of the products or services that they provide the market. Drop in a titillating industry tidbit to get his or her attention.

The chain is the body of your letter. It arouses the reader's interest and builds desire. This is where you present the benefits of exhibiting in your show. For each benefit or advantage the show provides the exhibitor, provide a corresponding feature that describes how the show delivers the benefit.

The hook closes your letter persuasively. Its purpose is to cause an immediate, favorable reaction -- to get the reader to take a positive buying step. A letter without a hook is like a sales call without a close. What do you want the reader to do? Be as specific in your letter as you would be on a sales call, and make your conclusion brief but strong. Too many words distract from your call to action. Use action verbs and avoid conditional words such as "if" and "should."

Here are some ways you can create your hook:

• Summarize your major idea with a new thought.
• Ask for the business in a direct appeal.
• Make a prediction.
• Ask a rhetorical question.
• Refer to what your prospect wants.
• Quote a source that backs your sales point.

People tend to remember beginnings and endings. Your star and hook may be the only parts of the letter the prospect reads. Make them count.

P.S. We're all suckers for a good postscript. I like to use the P.S. to drop in another juicy point and create a sense of urgency.