The following excerpt is from Robert W. Bly’s book The Direct Mail Revolution: How to Create Profitable Direct Mail Campaigns in a Digital World. Buy it now from Amazon | Barnes & Noble | Apple Books | IndieBound

For many products and offers, especially complicated ones, you’ll need to send a full direct mail package or a self-mailer to tell the story, present the facts, answer objections, and allow the consumer to place an order. But not all direct mail campaigns require you to do this in-depth—a postcard works well enough to do the job.

On a postcard, the space for graphics, copy, and the reply mechanism is much more limited, but they work great under these conditions: