Direct mail vs. email marketing: cost, response and when to use each

Cost per message and cost per response

An email costs a fraction of a cent to send. A 6×9 postcard costs about $0.58 to print and mail as Marketing Mail. On cost per message, email wins by a thousand to one. On cost per response, the gap narrows sharply: at a 1% click rate and a 0.1% conversion, an email campaign to 10,000 addresses produces about 10 conversions; a postcard campaign to the same 10,000 households at a 1% response produces about 100 responses for $5,800, or $58 each. Whether that is cheap depends on what a customer is worth, but for most local services and considered purchases it compares well with paid search and better with social.

Attention and lifespan

Email is read, if at all, in seconds and then buried; most marketing email is never opened. A postcard is handled by definition, read on the way from the mailbox, and often kept: UK research by Royal Mail's MarketReach found that mail stays in the home for days to weeks and is revisited. A card on the refrigerator is an ad that runs for a month. The USPS reports that most households look at their mail every day and that a large majority sort it immediately, which is attention email cannot buy.

Reach

Email reaches only the people who gave you an address and did not unsubscribe, which for prospecting means nobody. Direct mail reaches any household or business in the country from a purchased list, a saturation route or a new mover file, with no opt-in required. For acquisition, mail is often the only channel that can reach the exact audience; for retention, email is the cheaper way to stay in touch between mailings.

Measurement

Email measures itself: opens, clicks, conversions, in real time. Mail needs to be set up to measure: a tracking number, a QR code, a short URL, an offer code, and delivery scans to know when it landed. Set up that way, it measures as cleanly as email, with the advantage that a matched holdout group (households that qualified but were not mailed) gives a true incremental lift, which email rarely bothers to compute.

Running them together

The best programs use mail for what email cannot do and email for what mail cannot afford. Mail the offer to the list; email the same households the week the card lands, referencing it; retarget site visitors from the card's URL with a second card; email again with a deadline reminder. Households that receive both respond at a higher rate than either group alone, and the email is nearly free.

• Acquisition: mail (email cannot reach prospects)
• Nurture and reminders: email
• Win-back of unsubscribed or unresponsive customers: mail
• High-value accounts and considered purchases: mail, then email
• Weekly promotions to an engaged list: email, with a quarterly card