Direct Mail vs SMS Marketing
SMS has become a major e-commerce marketing channel with strong open rates. Direct mail is the physical alternative that works through a completely different mechanism. Here's how the two compare for Australian DTC brands.
Channel mechanics comparison
| Dimension | Direct mail | SMS |
|---|---|---|
| Cost per send | Higher (print + postage) | Low ($0.05–$0.10/msg) |
| Delivery speed | 3–7 business days | Seconds |
| Opt-in required (AU) | No (existing customers) | Yes (Spam Act 2003) |
| Open / read rate | High (physical, hard to ignore) | Very high (98% open) |
| Content format | Visual, branded, two-sided | Text only, 160 chars |
| Brand impression | Premium, tangible | Functional, immediate |
| Audience reach | Any existing customer with address | Opted-in subscribers only |
| Shelf life | Lasts until customer discards it | Read and gone in seconds |
The opt-in gap — direct mail's structural advantage
SMS marketing in Australia is regulated by the Spam Act 2003. You must have explicit consent from the recipient before sending a marketing SMS. This creates an opt-in audience that, while engaged, is smaller than your total customer base.
Direct mail to existing customers doesn't carry the same opt-in requirement. Any customer who has purchased from your Shopify store and has a delivery address on file can receive a postcard — regardless of whether they've opted in to email or SMS marketing. This makes direct mail's reachable audience significantly larger for many brands.
Where SMS wins
- Time-sensitive promotions — Flash sales, limited-time offers, or events where delivery timing is critical
- Transactional updates — Order confirmations, shipping notifications, appointment reminders
- High-opt-in audiences — Brands with strong SMS subscriber lists who have explicitly consented to marketing messages
- Short, action-specific messages — Discount code delivery, click-to-claim offers, simple CTAs
Where direct mail wins
- Lapsed customers who haven't opted into SMS — You can still reach them via a postcard
- Premium brand positioning — A physical postcard communicates quality that a text message can't match
- Visual creative that needs space — When you have artwork, imagery, or a message that can't be communicated in 160 characters
- Re-engagement after digital fatigue — Customers who have tuned out digital channels often still engage with physical mail
Using both channels together
SMS and direct mail are complementary rather than competitive. A common sequencing for win-back campaigns:
- SMS to opted-in lapsed customers first — fast, low cost
- Suppress customers who convert from the SMS
- Send a postcard to lapsed customers who didn't respond — reaches non-SMS-opted-in customers and provides a different medium for SMS non-responders
Related reading
Reach customers SMS can't — no opt-in required.
Any existing customer with an address can receive a postcard.
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