Postcards pack a powerful punch. With no envelope to open, even if the postcard is thrown away, there is no way for recipients to avoid being exposed to your message. That why it’s critical to maximize the use of space. You have very limited time and room to get your message across.

Here are five tips on getting the most out of your postcards from author, copywriter, and marketing consultant Robert W. Bly:

1. Keep it short

This is not the time to explain every benefit your product offers. Keep it brief and to the point. Bly recommends a maximum length of 100 to 150 words. This means you’ll have to write in terse, almost clipped prose. “Make sure each sentence gives the reader a new piece of information,” he writes. “You don’t have room to repeat yourself.”

2. Do a copywriter’s rough

Sketch out how you want the postcard to look once it’s printed. Rough out your headlines, subheads, captions, and bullets. This will help you focus your marketing copy.

3. Make the headline pay off right upfront

The promise of the headline should be immediately fulfilled in the body copy. Says Bly, “Your first few sentences should explain, elaborate on, and support the promise made in the headline.”

4. Stress benefits

This is the classic, “What’s in it for me?” If you sell lawnmowers, don’t give speeds and specs. Say, “Cut your lawn in half the time.” For details, Bly emphasizes, send them to your website. (We would add that if you create a campaign-specific landing page, this will allow you to track the results of your postcard mailing, too!)

5. Tell the prospect what to do

Bly reminds us how many people forget to add the call to action (CTA). Don’t assume people will pick up the phone, go to your website, or do what you want them to do, even if they love your product. Include a direct call and remind the recipient to take action.  It’s critical.