Direct Mail ROI: How to Measure What Your Postcards Are Worth
The biggest objection to direct mail is "how do I know it works?" Unlike brand advertising, automated postcard campaigns with unique promo codes and QR codes give you per-card attribution — the same measurement standard you expect from digital ads. Here's how to calculate your direct mail ROI and what benchmarks to aim for.
The ROI formula
Direct mail ROI = (Revenue attributed to campaign – Total campaign cost) / Total campaign cost × 100. Campaign cost includes card printing, postage, and any subscription fees. Revenue is tracked via unique promo code redemptions and QR code scans. With Mayday, every postcard gets a unique code, so attribution is exact — no guessing or modelling required.
Tracking attribution
There are two attribution methods for postcard campaigns. First: unique promo codes printed on each card, redeemed at checkout. Second: QR codes that link to a tracked landing page or product collection. Between the two, you capture both online redemptions and browsing behaviour. Mayday attributes all conversions automatically in your dashboard.
Benchmarks to aim for
Industry average direct mail response rate is 4.4% (ANA/DMA). Mayday merchants typically see 8–15% response rates on win-back campaigns and 5–10% on promotional campaigns. At an average postcard cost of €1.69–€2.39 and an average e-commerce order value of €60–€100, most campaigns achieve 5–15× ROI. Win-back campaigns targeting high-LTV lapsed customers consistently deliver the best returns.
Improving your ROI over time
Start with your highest-value segment (lapsed customers with high lifetime value). Test different offer depths — 10%, 15%, and 20% discounts — and measure which drives the best margin-adjusted ROI. Shorten or lengthen your inactivity trigger window. A/B test postcard designs. Every campaign generates data that improves the next one.
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