If you have looked at direct mail APIs, you have probably found PostGrid. It is well built, well documented, and aimed at a different job from the one a marketing team is trying to do. This guide compares Oppizi and PostGrid on what a campaign actually needs, from the volume their plan allows through to cost per piece, who you can reach, and whether you can prove the mail worked.
What is Oppizi
Oppizi is the offline marketing platform powered by agentic technology. On the direct mail side that includes addressed mail, EDDM (Every Door Direct Mail), shared mail, USPS Informed Visibility tracking, QR code tracking, lookalike audience modelling, and personalisation at scale, with print-and-ship inside 24 hours through the largest printer network in the USA.
Underneath it is Soleon, Oppizi's proprietary agent infrastructure. Copilot for campaign planning and the Oppizi MCP both run on it, so a marketer can plan, launch, and read results from inside Claude or ChatGPT, not only from a dashboard. Oppizi operates in over 12 countries and can launch in any market, and direct mail is one of three offline channels on the platform.
Oppizi vs PostGrid comparison at a glance
PostGrid is an API-first platform for offline communications, built around letters, cheques, statements and address verification. Here is how the two compare on the criteria marketing teams evaluate.
| Feature | Oppizi | PostGrid |
|---|---|---|
| Monthly platform fee | None | $0 Starter, Enterprise quote only |
| Self-serve volume ceiling | No cap | 500 mailings per month, then overage fees |
| Published cost per piece | $0.54–$0.61 addressed, data included | $0.902 4x6 postcard First Class, $0.987 6x9 Standard, letters $0.827 to $1.219 |
| Audience data included in pricing | Yes | No, List Builder sold as credits, price unpublished |
| Lookalike audience modelling | Yes | Not published |
| Holdout testing for incremental lift | Yes | Not published |
| A/B and split testing | Yes | Not published |
| pURL and QR response tracking | Yes | Yes |
| USPS scan-level mail tracking | Yes | Yes, IMB |
| Conversion tracking | Yes | Yes |
| Countries with published mailing prices | 12+ countries | US and Canada |
| Every Door Direct Mail (EDDM) | Yes | Not published |
| Shared mail | Yes | Not published |
| Package inserts channel | Yes | No |
| Flyering channel | Yes | No |
| Cheques, statements and notices | No | Yes, a core product |
| Address verification as a product | Not published | Yes, separately priced |
| Managed service | Yes, full-service or self-serve | Not published, white-label partner tiers |
| Launch campaigns from an AI assistant | Yes, Oppizi MCP | Not published |
| Production turnaround | 24-hour print-and-ship | 2-day SLA |
PostGrid per-piece prices include printing, processing and postage, and are quoted from their published Starter rate card. Verified against their pricing pages on 8 September 2026.
The 500-piece ceiling
Start with the constraint that decides everything else. PostGrid publishes two plans. Starter costs nothing a month and allows up to 500 mailings a month, and their own documentation states that going over that on Starter means paying an overage fee. Above it there is one option, Enterprise, priced at "let us talk".
Five hundred pieces is a pilot, not a campaign. A modest acquisition test is 10,000 to 20,000 pieces, which means a marketing team evaluating PostGrid is not comparing platforms, it is entering a sales cycle before it knows the price. Oppizi has no monthly fee and no volume cap. You pay per piece from the first piece to the millionth, and the rate is published.
Cost per piece, and what is inside it
Oppizi addressed direct mail runs approximately $0.54–$0.61 per piece with audience data included: targeting lists, demographic overlays and purchase-intent signals are in the per-piece cost. For EDDM, the all-in cost including postage is approximately $0.45 per piece.
PostGrid publishes $0.902 for a First Class 4x6 postcard, $0.987 for a Standard Class 6x9, and $0.827 to $1.219 for letters, all including printing and postage. Their mailing data is a separate purchase, bought as credits through an account executive, and the per-contact price is not published at all. So the comparison is a known number with data inside it against a higher number with an unquoted number on top.
Tip: when comparing direct mail platforms, look at the total direct mail cost: plan fee, per-piece rate, data, and any volume the plan will not carry. A quote that looks close on one line rarely stays close across all four.
Built for statements, or built for campaigns
PostGrid does transactional mail properly. Cheques with MICR encoding, statements, invoices, policy documents, notices, snap packs, certified mail, address verification with autocomplete and geocoding APIs. If your requirement is getting a document to a named person reliably and provably, that is the right stack, and Oppizi does not compete for it.
A campaign asks different questions. Who should receive this, out of everyone who could. Which creative earned the response. What would have happened if we had mailed nobody. PostGrid publishes no A/B testing, no split testing, no control groups, no holdout capability and no incremental lift measurement. Their analytics guidance is about techniques you assemble yourself with coupon codes and unique phone numbers. The primitives are there; the experiment is not.
Proving the campaign caused the outcome
On Oppizi a holdout group is standard on every campaign. A portion of the target audience deliberately receives no mail, which isolates what direct mail actually caused from what would have happened anyway, and the live dashboard reports incremental lift alongside response rate and CPA, split by geography and creative variant.
Both platforms track delivery and response. PostGrid publishes IMB scan tracking, QR codes, personalised URLs and conversion metrics, and those are real. The gap is the experiment on top of them: without a control group, a response rate is a number without a counterfactual, and that is the number a budget review asks about.
Reaching households that are not on a list
PostGrid sells US consumer and business records through List Builder, filterable by age, income, education, occupation and geography, so prospecting is possible if you buy the file. What is not published is any modelling on top of it. Oppizi builds lookalike audiences from your own best customers, drawn from a performance database that learns from past campaigns, and audience intelligence layers first-party and third-party signals, with the data already in the per-piece price.
And sometimes the audience is a map rather than a file. EDDM delivers to every address on a carrier route with no names at all, at approximately $0.45 per piece all-in, which is how new store openings and local saturation campaigns get run. PostGrid publishes no EDDM product and no EDDM pricing, and no shared mail.
Automation a marketer can drive, and an AI assistant can drive too
The PostGrid API is the product, and it is thorough: letters, postcards, cheques, address verification, webhooks, test and live keys, and integrations with Salesforce, HubSpot, Marketo and more, though native integrations sit on the Enterprise tier and Starter includes only Zapier and Stripe. Oppizi integrations connect Shopify, Braze and other marketing platforms for programmatic and triggered direct mail, and direct mail retargeting is built in.
The part with no equivalent is Soleon. Because Copilot and the Oppizi MCP run on the same agent infrastructure, a marketing team can plan an audience, launch a campaign and read incremental lift from inside Claude or ChatGPT with one sign-in. PostGrid publishes one AI capability, an address parser, and no agent integration.
Direct mail results from leading brands
The numbers tell the story better than claims:
- UberEats: direct mail and flyering across four markets, 2M+ new customers at a 2% conversion rate
- The Iconic: addressed direct mail in Australia, 76,800 new customers, verified with incremental holdout testing
- Getaround: flyering in the US, CPA cut 70% versus digital channels
Each of these is a scaled campaign with tracked outcomes, not a pilot. Oppizi has delivered more than 306 million pieces in over 12 countries, with every campaign attributed through QR codes, unique URLs, and promo codes, so you read your own figure rather than an industry estimate.
Beyond direct mail with package inserts and flyering on one platform
Direct mail is one of three offline channels Oppizi runs. If mail is already working, the same platform, the same targeting, and the same attribution extend into other physical touchpoints.
Package inserts place your offer inside outgoing orders from partner brands, reaching a customer at the moment they open a package. Hand-to-Hand and Door-to-Door flyering puts Brand Ambassadors in high-traffic areas and flyers on residential doors, tracked with the same rigour as mail. PostGrid offers neither.
Make the switch from PostGrid to Oppizi
If you are evaluating PostGrid alternatives for marketing rather than transactional mail, Oppizi is a performance marketing platform built for it: no monthly fee, no volume cap, lower cost per piece with data included, holdout testing on every campaign, EDDM and shared mail, over 12 countries, and agent-native automation on Soleon.
