SMS is the most immediate channel in your owned stack. Messages are read quickly, and a well-built program can drive meaningful revenue from a small list. It is also the most regulated and the easiest to overdo. This guide covers how to build SMS that earns subscriber trust and revenue.
Why SMS works for ecommerce
- Immediacy. Time-sensitive moments, such as a restock, a flash sale ending, or an order shipping, fit SMS better than email.
- Personal feel. A text lands in the same place as messages from friends, so tone and relevance matter more.
- Strong conversion intent. Subscribers who opted in to text are usually higher-intent.
- Complements email. Use SMS where speed matters and email where there is more to say.
What SMS is not
SMS is not a copy of your email calendar. Sending the same promotion on both channels at the same time is one of the most common ways to burn out a list.
Step 1: Choose your platform and sender
Most Shopify brands choose between Klaviyo SMS and a dedicated platform such as Postscript. Compare on:
- Integration with your email platform and data
- RCS support and fallback behavior
- Compliance tooling and support
- Pricing model (messages, credits, and carrier fees)
- Strategy and support access
See Best SMS Platforms for Shopify Brands and Postscript Launches Email for the latest on the landscape.
Step 2: Get compliance right first
Compliance is not optional, and the penalties are real. Work with legal counsel, and build these basics into every program:
- Express written consent before any marketing text, with clear disclosure of what subscribers are signing up for, message frequency, rates, and how to opt out
- Consent records you can produce if challenged
- Easy opt-out (STOP) honored immediately
- Quiet hours respected by recipient time zone
- Sender registration with carriers (10DLC for local numbers, or a toll-free or short code route)
- No purchased lists
For a full walkthrough, read SMS Compliance for Ecommerce. This guide is general information, not legal advice.
Step 3: Grow the list
| Method | How it works | Note |
|---|---|---|
| Two-step pop-up | Email first, then phone number with SMS consent | Usually higher quality than a single combined form |
| Checkout opt-in | Consent checkbox at checkout | Strong for converting buyers |
| Keyword opt-in | Text a keyword to a number | Good for ads, packaging, and events |
| Social comment-to-DM | Comment keyword, receive DM, opt in | See Klaviyo Social Marketing |
| Post-purchase prompt | Invite buyers on the thank-you page or in email | Often overlooked |
| Landing pages and QR codes | For direct mail, retail, and out-of-home | Pair with direct mail |
Offer a reason to join beyond a discount: early access, restock alerts, exclusive drops.
Step 4: Build the core SMS flows
| Flow | Trigger | Message goal |
|---|---|---|
| Welcome | New SMS subscriber | Confirm, deliver the offer, set expectations |
| Abandoned cart | Cart left | Recover quickly with a short nudge |
| Browse abandonment | Product viewed | Light reminder for engaged browsers |
| Order confirmation and shipping | Order events | Transactional value with brand voice |
| Post-purchase | Days after delivery | Review request, cross-sell, replenishment |
| Back in stock | Restock | Convert waitlist demand |
| Winback | Lapsed customer | Reactivate with a relevant reason |
Keep texts short, specific, and tied to a clear action.
Step 5: Plan campaigns sparingly
Good SMS campaigns:
- Announce something genuinely time-sensitive
- Go to a defined segment, not always the full list
- Include one link and one clear call to action
- Use MMS or RCS when imagery or product cards add value
A useful guideline is to treat each SMS as a privilege. If a message does not have a reason to be a text, send it by email.
Step 6: Write messages people actually read
- Identify your brand in the first words
- Lead with the value, then the link
- Write the way a helpful person would text, not like an ad
- Use personalization that adds information, such as product or order details
- Test emojis and length rather than assuming
Step 7: Consider RCS
RCS adds rich media, carousels, and verified sender profiles on supported devices, with SMS as fallback. It is worth testing for launches and post-purchase, with a holdout to measure lift. See RCS vs SMS.
Step 8: Coordinate SMS and email
A simple coordination model:
| Moment | Lead channel | Support channel |
|---|---|---|
| Product launch | Email (story and detail) | SMS (go-live alert) |
| Flash sale | SMS | |
| Cart abandonment | SMS first for speed, email follow-up | |
| Order and shipping | SMS | Email receipt |
| Content and education | None |
Use suppression logic so a person who just purchased from an email does not get a text about the same offer. See SMS vs Email.
Step 9: Measure and optimize
| Metric | What it tells you |
|---|---|
| Revenue per message | Efficiency of each send |
| Click rate | Message and offer relevance |
| Conversion rate | Landing experience and intent |
| Opt-out rate | Whether you are sending too much or the wrong thing |
| List growth and net growth | Health of acquisition |
| Incremental revenue (holdout) | True contribution of the channel |
Watch opt-out rate closely. A rising trend is an early warning to cut frequency or sharpen segmentation.
Common SMS mistakes
- Sending the same message as email at the same time
- Blasting the full list every time
- Ignoring compliance details until a problem appears
- Over-discounting
- Skipping flows in favor of campaigns
- Not measuring incrementality
SMS program checklist
- ☐ Consent language reviewed by counsel
- ☐ Sender registered and approved
- ☐ Welcome, cart, and post-purchase flows live
- ☐ Quiet hours and time zones configured
- ☐ Suppression logic between SMS and email
- ☐ Holdout testing running on at least one flow
- ☐ RCS test planned
- ☐ Monthly review of opt-outs and complaints
FAQ
How often should I text subscribers?
Start conservatively and let engagement and opt-out rates guide you. Frequency should vary by segment.
Is SMS worth it for small lists?
Often yes, because revenue per subscriber can be high, but test with a clean, consented list.
Do I need a separate platform from my email tool?
Not necessarily. Many brands use Klaviyo for both. Others pair a dedicated SMS platform with Klaviyo email.
Can I text anyone who bought from me?
Not without proper marketing consent. Transactional messages and marketing messages have different rules.
How ATTN helps
ATTN builds SMS and RCS programs on Klaviyo and Postscript, including list growth, compliance-ready flows, creative, and testing. Talk to our retention team about an SMS audit.
ATTN is a marketing agency, not a law firm. This article is general information, not legal advice. Laws and carrier rules on consent, messaging, and privacy change often and vary by state and situation, so consult your own attorney before making decisions about your program.