When planning a direct mail campaign, one of the biggest decisions you’ll make is whether to send a traditional letter in an envelope or a postcard. Both formats have their strengths and weaknesses. To get the best return on investment (ROI), it’s important to understand how each format performs in terms of open rates, perceived value, cost, and campaign goals.
In this blog, we’ll break down the key differences between letter mail and direct mail postcards, and help you decide which is right for your next campaign.
Understanding the Letter Mail & Direct Mail Postcard Formats
Letter mail, sometimes referred to as lettermail, typically includes a folded letter or insert enclosed in an addressed envelope. This is the classic format used for more formal communications. It gives you more space to write, allows for multiple inserts, and offers an added layer of privacy.
Postcards, on the other hand, are open-faced pieces of mail. There’s no envelope, so your message is visible as soon as the recipient picks it up. Postcards are usually printed on heavier cardstock and often feature bold graphics and quick, punchy messaging.
Direct Mail Open Rates and Attention
One of the key differences between the two formats is how they’re received. Postcards don’t need to be opened, so your message is instantly visible. This can work in your favor if the design and headline are strong enough to catch someone’s attention in the few seconds they spend sorting their mail.
Letter mail, however, creates a sense of curiosity. People are often more inclined to open an envelope addressed to them, especially if it looks personal or official. Because it’s not immediately obvious what’s inside, a well-designed envelope can boost open rates significantly.
While postcards rely on instant visibility, letter mail encourages deliberate engagement. If your goal is to get your message read with more care, letter mail tends to have the advantage.
Perceived Value and Impact of Lettermail Vs. Direct Mail Postcards
Letter mail often feels more important. Recipients usually associate envelopes with meaningful communication—such as bank statements, medical notices, or personal invitations. That perception increases the chances that the letter will be opened, read, and even kept for future reference.
Postcards, while more affordable, are often viewed as promotional. They’re eye-catching but tend to feel more disposable. This doesn’t make them ineffective, but it does affect how people treat the message. Postcards are great for fast promotions, but letter mail is better suited for messages that require attention or trust.
Cost Considerations
Postcards are generally more cost-effective. Because they don’t require envelopes or additional labor for stuffing, printing and processing costs are lower. Postcards also qualify for lower postage rates when mailed in bulk, making them a strong option for wide-reaching campaigns.
Letter mail, on the other hand, costs more to produce and send. You’re paying for more materials and labor, and postage rates are usually higher. However, if the message leads to a higher-value conversion or longer-term customer engagement, the cost may be justified.
Matching Format to Campaign Goals
The format you choose should depend on what you want your campaign to accomplish. If you’re running a time-sensitive promotion, offering a discount, or simply trying to build awareness, a postcard may be the right tool. The bold visuals and fast-read format are perfect for quick calls to action.
But if you need to explain something in detail, present an offer with multiple steps, or communicate a more serious message, letter mail is often the better choice. It gives you more room to write and allows you to guide the reader through a thoughtful pitch.
Which Direct Mail Marketing Format Works Best by Industry?
Different industries tend to benefit from different formats based on the type of message they need to send and how their customers prefer to receive it.
For financial institutions, insurance providers, and healthcare companies, letter mail is typically the better option. These industries often deal with sensitive or personalized information and require more space to explain complex offers or instructions. The envelope also signals a level of professionalism and confidentiality that’s expected in these sectors.
Retailers, restaurants, gyms, and local service providers often find more success with postcards. The format is ideal for announcing seasonal promotions, grand openings, loyalty offers, or reminders. The lower cost and faster turnaround make postcards a practical solution for frequent, high-volume campaigns.
Real estate professionals can benefit from both. Postcards work well for general farming and brand awareness, while letter mail is ideal for targeted outreach to homeowners, buyers, or sellers with a more personal touch.
For non-profits, letter mail typically performs better when requesting donations or sharing stories. The format allows for emotional storytelling and personalization, both of which are critical for engagement and conversion.
There is no single “winner” between letter mail and postcards. The truth is, both formats are incredibly effective when used strategically. Postcards are great for grabbing quick attention and delivering short, impactful messages. Letter mail offers more space, greater perceived value, and a higher level of personalization.
The best choice depends on your message, your audience, your budget, and your campaign goals.
Not sure which format is right for you? At Torpedo, we specialize in helping businesses make the most of their direct mail marketing. Whether you’re considering a bulk mail postcard campaign or a customized letter mail package, our team can help you plan, design, and execute with confidence.
Contact Torpedo today to find out which format is best for your next direct mail campaign.
