Postcard Marketing: When to Send a Postcard or a Letter

Postcard marketing is mailing a printed card with no envelope to customers or prospects. It suits a short message to people who already know you. For a first contact with a business owner, a letter in an envelope fits better. In the ANA's 2021 survey of marketers, postcards gave the best return on house lists and letter-sized envelopes on prospect lists.

This guide compares the two honestly, from postage to privacy. It is written for agencies and freelancers who sell to local businesses, and who may also run postcards for those clients.

What is postcard marketing?

Postcard marketing is sending a single printed card through the post as an advertisement, a reminder or an invitation. Nothing has to be opened. The reader sees the message on the walk from the mailbox to the desk or the bin.

Many postcards go from local businesses to households. A dentist reminds patients about a checkup. A roofer writes to the streets around a finished job. Most guides on the subject are written by printers for those businesses.

An agency meets postcards in two ways. You can post them yourself, to clients and prospects. You can also run them as a service for a client who sells to households. This post is mainly about the first, and the comparison holds for both.

Postcard or letter, which should you send?

Send a postcard to people who know you and a letter to people who do not. A postcard is a reminder. A letter is an introduction.

The postage figures are the US Postal Service prices that took effect on October 4, 2026 (USPS Notice 123). The word counts are our own working limits.

What does the data say about postcards and letters?

The clearest public figures come from the ANA's Response Rate Report 2021, released on January 24, 2022. Postcards gave the best return on house lists, at 92%. Letter-sized envelopes gave the best return on prospect lists, at 112% (ANA).

A house list is a list of people who already know you, such as clients and past clients. A prospect list is a list of people who do not.

Four limits apply. The figures are return on investment, and the press release gives no response rates. The survey drew on 581 qualified responses from marketers in several industries. It is from 2021. And only 38% of those marketers used direct mail at all.

For a response rate, the nearest figure is secondhand. Prospect lists average a 4% to 5% response, depending on format and targeting, according to PI World, citing the 2024 ANA Response Rate Report. PI World is a trade magazine, and the report itself is for ANA members only, so we could not read it.

So treat the finding as direction. Our reading of it is plain. A card from a name you recognize gets a glance, and a glance is enough for a reminder. A card from a stranger is an ad. A sealed letter with your name on it asks for one minute, and it can give a reason.

What do direct mail postcards cost to post?

A postcard costs $0.65 to post and a 1-ounce stamped letter costs $0.82, under the US Postal Service prices that took effect on October 4, 2026 (USPS Notice 123). The gap is 17 cents a piece. On 200 pieces that is $34.

Size decides whether you get the postcard price. To qualify, a card must be at least 3-1/2 inches high by 5 inches long, and no more than 4-1/4 inches high by 6 inches long. It must also be between 0.007 and 0.016 inch thick (USPS Business Mail 101).

The same page says what happens to a bigger card. "If your mailpiece does not meet the dimensions above, then the Postal Service considers it a letter and letter-size postage is charged."

So an oversized card saves nothing on a stamp. It still has no envelope to buy or fill, and that saving remains.

Postage is one part of the bill. Print, the list and your time come on top, and our post on direct mail cost goes through each.

When does a postcard beat a letter?

A postcard wins when the reader already knows your name and the message fits in one line. Five cases stand out.

1. A reminder to a client. A care plan is up for renewal, or the site is due a checkup.
2. An invitation. A workshop, an open evening or a webinar with a date on it.
3. News. A new address, a new service or a new team member.
4. A later touch. A card to a prospect who has already had your letter and your emails.
5. A client's own campaign. A roofer who writes to the streets around a finished job needs a postcard, and you can run that for them.

In each case nothing private is said and nothing needs explaining.

When does a letter beat a postcard?

A letter wins at first contact, and whenever the message is about the reader's own business. There are three reasons.

Privacy. The reason an agency writes to an owner is usually a weakness on their website. "Your booking form fails on a phone" is useful inside an envelope. Printed on a card, it is read by the front desk and the mail carrier first.

Room. A good first letter names what you saw, says what it costs the owner and asks for ten minutes. That takes about 120 words, by our estimate. A card has room for a third of that.

The look of correspondence. A stamped envelope addressed by name is opened as mail. A glossy card is sorted as advertising.

The sequence in Leadodo starts with a letter too. Your Outbound Machine opens with a posted letter that arrives on day 1, and Twip's findings about the business's website become its opening line. Emails and LinkedIn steps follow, and the whole sequence takes 19 working days.

Our pillar on direct mail for agencies explains the order. The guide on how to write a sales letter covers the page itself.

What goes on a postcard to a client?

One line on the front and about 40 words on the back. The front carries the single message. The back says who the card is from, what to do and how.

The card below is made up. The studio, the flooring store and the web address do not exist.

Front. Your website care plan ends on February 28.

Back. Hi Mark. Your care plan for pruittflooring.example runs out at the end of the month. This year it covered 14 updates and two repairs. To keep it going, call Jo on 555-0183 or write to hello@halyardweb.example.

Halyard Web Studio

Four rules keep a card readable.

• One message. A card with three offers has none.
• A name. "Hi Mark" on a card to a client costs nothing and changes how it reads.
• One next step. A phone number that a person answers.
• Nothing private. Leave out anything you would mind a stranger reading.

For more formats and layouts, see our direct mail examples for B2B.

Can you use a postcard and a letter together?

Yes. Let the letter go first and the card come later. The letter introduces you and carries the private finding. A card some weeks later reminds the owner of a name they have now seen.

We have no data on whether that later card adds replies. Test it on a small batch before you print 500.

The broader guide to direct mail marketing covers how to measure a test like that. The direct mail campaign plan shows where a card would sit in the calendar.

Questions

Is postcard marketing effective?

For people who know you, the evidence is fair. In the ANA's 2021 survey, postcards gave the best return of any mail format on house lists, at 92%. On prospect lists, letter-sized envelopes did best.

How much does it cost to mail a postcard?

Postage is $0.65 for a card that meets the US Postal Service's postcard size, under the price list of October 4, 2026. A larger card pays letter postage, which starts at $0.82. Print and your time come on top.

What size should a marketing postcard be?

To get the postcard price, between 3-1/2 by 5 inches and 4-1/4 by 6 inches. A bigger card has more room and pays letter postage. Choose on the message, then check the price.

Are postcards or letters better for B2B prospecting?

Letters. A first message to a business owner is usually about a weakness in their business, and that belongs in an envelope. Keep postcards for clients, past clients and prospects who already know your name.

Do postcards need a mailing list?

Addressed cards do. The US Postal Service also offers Every Door Direct Mail, which reaches "customers in targeted neighborhoods, without having to provide names or street addresses" (USPS). That suits a client who sells to households. An agency that writes to owners needs names.

How many words fit on a postcard?

About 40 on the back, by our estimate, plus one line on the front. If the message needs more, it is a letter.

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Next step. See the 19 working days your Outbound Machine runs, from the letter that arrives on day 1 to the last LinkedIn step. Outbound Machine.