SMS marketing: the operator's ultimate guide
SMS marketing is the fastest-growing owned-channel category for DTC and consumer brands. 95%+ open rates, 10-30% click rates, and 3-10x revenue per recipient vs email. The catch: SMS costs $0.01-$0.05 per send (vs near-zero for email), TCPA compliance is non-negotiable, and unsubscribe damage is permanent. This guide is the long version.
Why SMS works
- The phone is the most-checked surface in most consumers' lives.
- SMS reaches the lock screen with no algorithm gating.
- Subscribers actively opted in — quality is higher than purchased email lists.
- Short, urgent format produces fast response.
The platforms
| Platform | Best for |
|---|---|
| Klaviyo SMS | DTC brands already on Klaviyo email — unified flows and segments |
| Attentive | DTC SMS specialist with deep feature set |
| Postscript | DTC SMS specialist, Shopify-centric |
| SimpleTexting, EZ Texting | SMB-friendly SMS platforms |
| Twilio | Developer-first API for custom programs at scale |
| HubSpot | B2B SMS extensions tied to CRM workflows |
TCPA compliance — non-negotiable
US Telephone Consumer Protection Act requires explicit, written, opt-in consent for marketing SMS. Penalties run $500-$1,500 per unauthorized message. The discipline:
- Explicit opt-in via checkbox at signup (not pre-checked).
- Disclose data rates may apply, frequency expectation, and STOP-to-opt-out.
- Honor STOP requests immediately.
- A2P 10DLC registration with carriers (required since 2023). See Twilio.
- Document consent records — auditable proof for legal defense.
Full guide in TCPA compliance.
List growth
SMS list quality matters more than email list size. The growth tactics:
- Checkout opt-in (the highest-value moment).
- Email-to-SMS upgrade (existing email subscribers asked to add SMS).
- Welcome pop-up offering SMS-exclusive discount.
- SMS-only product launches (creates incentive for non-subscribers to join).
- Keyword-to-join (text JOIN to a short code).
Full discipline in SMS list growth.
The SMS flows that work
FIG. 01 — SMS flow architecture
- Welcome. 2-3 messages over 24-72 hours establishing trust.
- Abandoned cart. 1-2 messages within 1-4 hours. Highest-ROI SMS flow.
- Order confirmation + shipping updates. Transactional; counts as utility messaging.
- Replenishment. For consumable categories.
- Win-back. Re-engagement after 60-90 days inactive.
- Time-limited offers / flash sales. SMS urgency outperforms email here.
SMS economics
RGM Experts Say
The unsubscribe rate is the SMS metric we watch hardest. Email's marginal send cost is near-zero, so high unsubscribes hurt deliverability but not unit economics. SMS unsubscribes hurt both. We target under 1% unsubscribe per send. If we creep above 2%, we cut frequency immediately — even if revenue per send is climbing. The math: you spent $5K acquiring a subscriber; one bad week of SMS at high frequency burns 5-10% of the list. That's 5-10% of your acquisition cost gone. Frequency restraint is how SMS programs survive year two.
| Metric | Typical range |
|---|---|
| Cost per send | $0.01-$0.05 |
| Open rate | 95%+ (essentially universal) |
| CTR | 10-30% |
| Conversion rate | 2-10% on offers |
| Revenue per recipient | 3-10x email |
| Unsubscribe rate | 0.5-2% per send (much higher than email) |
How SMS fits the broader stack
- Paired with email — SMS for urgency, email for depth.
- Driven by marketing automation platform.
- Part of lifecycle marketing.
- Tracked via UTMs into GA4.
- Compliance via TCPA discipline.
Klaviyo SMS or Attentive/Postscript?
For brands already on Klaviyo email, Klaviyo SMS is the clean choice (same audience, flows, reporting). Attentive and Postscript compete on feature depth but lose on data integration.
What's A2P 10DLC?
US carrier requirement for business SMS. All commercial senders must register their numbers and use cases. 1-3 weeks to register; required before scaling.
How aggressive should SMS frequency be?
Conservative beats aggressive. 4-8 messages per month maximum for most consumer brands. Higher frequency drives short-term revenue but accelerates unsubscribes.
Is SMS worth the cost?
For DTC consumer brands, almost always yes. Revenue per recipient 3-10x email, even after the higher per-send cost. ROI compounds with list quality, not raw size.
How do I avoid TCPA fines?
Explicit opt-in via unchecked checkbox at signup. Disclose terms. Honor STOP immediately. A2P 10DLC registration. Document consent records. Full TCPA guide.
SMS or RCS in 2026?
SMS still dominates in the US; RCS (Rich Communication Services) is rolling out but adoption is uneven. Treat RCS as a future-state opportunity; build on SMS today.
Operating checklist
- Define the business outcome before opening tools or platforms.
- Configure measurement, audit baseline metrics, document the starting point.
- Onboard first-party data; verify quality and coverage.
- Build the foundational programs before advanced layers.
- Launch with controlled budget; monitor daily for 14 days.
- Pull weekly performance and quality reports.
- Refresh quarterly based on what's compounding.
- Document the runbook so the next operator can pick it up.