For a first mailing to homeowners who don't know you, especially one that shows their own roof, a sealed letter is usually the better choice. In USPS Marketing Mail it pays the same postage as a postcard, it has room to explain what the photo shows, and it keeps your read on their roof between you and them. Postcards earn their place when the message is short and fine for anyone to read: past customers, storm notices, follow-ups, and small First-Class batches where card postage is noticeably cheaper.
This post compares postcards vs letters for roofing direct mail on four points: postage, all-in cost per response, what each format can carry, and who sees the piece before the homeowner does. It ends with a simple rule for choosing.
What does postage cost for each format?
The gap depends on the mail class. First-Class Mail has its own, lower price for postcards. USPS Marketing Mail, the bulk class for advertising mail, does not: the USPS guide to postcard sizes says there is no separate postcard price in Marketing Mail, so a card pays what a letter pays. Marketing Mail also needs at least 200 pieces or 50 pounds per mailing.
| Mail class and price level | Postcard | Letter (1 oz) |
|---|---|---|
| First-Class, single piece (stamped) | $0.65 | $0.82 |
| First-Class presorted, automation 5-digit | $0.453 | $0.621 |
| First-Class presorted, automation mixed AADC | $0.495 | $0.707 |
| USPS Marketing Mail, automation (5-digit to mixed AADC) | Same as a letter | $0.395 to $0.467 |
Prices are from USPS Notice 123, the version effective October 4, 2026. So a postcard saves about 17 cents a piece in First-Class Mail and nothing in Marketing Mail. One catch: the card price only applies inside the card size and thickness limits in the Domestic Mail Manual, section 201, which caps cards at 0.016 inch thick. A heavier or oversized card pays letter postage.
What does each format cost once printing is included?
Postage is only part of the bill. A letter also costs more to print, because of the envelope, the folding and the inserting. Take example print prices of $0.18 for a 6x9 postcard and $0.30 for a one-page color letter in an envelope, and postage at the 5-digit automation level. The all-in prices per piece then look like this:
| Example, print and postage | Marketing Mail | First-Class |
|---|---|---|
| 6x9 postcard | $0.575 | $0.633 |
| Color letter, one page | $0.695 | $0.921 |
| Extra responses the letter needs to break even | 21% | 45% |
Here is what that means per 1,000 homes. In Marketing Mail, the postcards cost $575 and the letters $695. Say the postcard brings in 5 calls, an example number rather than a benchmark. That's $115 per call. The letter matches that at about 6 calls (695 divided by 115), which is 21% more.
In First-Class the gap is wider: $633 for the cards and $921 for the letters. The letter now needs about 7.3 calls to match the card's 5, which is 45% more.
Print prices swing with size, paper and quantity, so plug in your own written quotes and your own call counts. The real question isn't which piece is cheaper. It's whether the letter can beat the card by that margin for your market and your message. And calls are only the first step: our guide to cost per job, not cost per piece carries the same math through to signed jobs.
Which format gets better results?
No independent study tests roofing postcards against roofing letters. The best public cross-industry numbers are a few years old and self-reported. In the ANA's Response Rate Report 2021, based on 581 qualified survey responses from marketers collected February to July 2021, letter-sized envelopes produced the best ROI of any format sent to prospect lists, at 112%. Postcards produced the best ROI to house lists, at 92%. The ANA published a 2025 edition, but its figures are for logged-in readers only, so they aren't used here.
Keep the limits in mind. These are marketers' own results across all industries, with no control groups and ROI as each company calculated it. One plausible reading of the split: people who already know you will act on a short card, while strangers need more convincing.
The envelope matters as well. In a study of 677 direct mail campaigns published in 2013, the design of the outer envelope drove whether people opened the mail, while personalization and clear sender information inside drove whether they kept it. A postcard skips the opening step, so its whole message is seen at the mailbox. A letter has to earn the open, then has room to do more once it's in someone's hands.
What can each format carry?
A postcard holds one image, a headline, a few lines of copy, a phone number and a QR code. That's enough for "we're replacing roofs on your street this month," a hail notice for a neighborhood, or a reminder about a free inspection.
A letter gives you a full page or more. That's room for a larger aerial photo of the house, a plain description of what it shows, where the image came from and roughly when it was taken, why this house got a letter, and a signature from a real person. You can also add an insert, like a reference list or a warranty sheet. Our post on what personalization research shows explains why that explaining matters when the mail is about someone's own roof.
Who else sees a postcard?
Everyone who handles it can read it: the carrier, whoever brings in the mail, a guest who sees it on the counter. For a generic offer that's harmless. For a photo of one specific house with a note like "missing shingles on the back slope," it's different. The homeowner may not want that out in the open, and an assessment of their roof sitting on an open card is closer to the invasive kind of personalization than the helpful kind.
There's a digital side too. USPS Informed Delivery emails subscribers grayscale images of the address side of letter-sized mail that runs through its automated equipment, and postcards count as letter-sized. If your message and photo sit on the address side, they may land in the homeowner's inbox before the card does. For a generic card that's a free extra look. For a sealed letter, only the envelope shows.
A simple rule for choosing
Send a sealed letter when:
- it's your first contact with a homeowner who doesn't know your company,
- it shows their house or says anything specific about their roof,
- you need room to explain where the image came from and what it shows,
- you're mailing Marketing Mail, where postage is the same either way.
Send a postcard when:
- the reader already knows you, such as past customers,
- the message is generic and fine for anyone to read, such as a storm notice or a seasonal inspection offer,
- it's a reminder to homes that didn't respond to an earlier letter,
- you're mailing small First-Class batches, where a card saves about 17 cents a piece.
The two also work together. A letter can open the conversation and a card a week or two later can remind the homes that didn't call. Give each piece its own tracking number or QR code so you know which one actually produced the call.
Where Scoutbound fits
Scoutbound is a done-for-you direct mail service built around the first case on that list. It analyzes aerial images of homes in ZIP codes chosen with the roofer, selects homes whose roofs show visible wear, and mails each homeowner a personalized letter with an aerial image of their own roof, sent under the roofer's brand, by USPS Marketing Mail. The image is used as a relevance signal after the roof's condition has been checked, which is the kind of content this post suggests keeping inside an envelope. Postage and printing are included. Each letter carries its own QR code and a tracking phone number, and calls, texts and scans show up in the roofer's online portal.