SMS and email are not rivals; they do different jobs. Email carries the story and detail. SMS delivers short, time-sensitive nudges. The skill is in giving each a clear role.
SMS marketing is regulated and rules differ by country. Treat this as general guidance and check the requirements for the regions you send to.
Where email is stronger
- Rich content: education, storytelling, product guides and layouts.
- Lower cost per message, so you can send to a larger audience.
- Longer flows such as welcome series and post-purchase education.
Where SMS is stronger
- Time-sensitive prompts: restock alerts, flash sales, delivery updates.
- Abandoned cart nudges as a second touch.
- Replenishment reminders at the moment a customer is about to run out.
Consent first
Collect clear, specific opt-in for text messages at sign-up and checkout, explain frequency and how to opt out, and honor unsubscribes immediately. Never text a number without consent.
Coordinate both channels
| Moment | SMS | |
|---|---|---|
| Abandoned cart | Reminder with product details | Short follow-up if no action |
| Replenishment | Heads-up before run-out | Brief nudge on run-out day (timing guide) |
| Launches | Story and details | "It's live" alert |
| Welcome | Full series | Optional single message |
Use flow logic so a customer who converts after the email does not also get the text. Keep SMS volume lower than email: each message feels more intrusive. For the overall setup, see the Shopify flow guide, and for how the pieces fit in Klaviyo, what is Klaviyo.
Quick answers
Is SMS better than email for ecommerce?
Neither is universally better. SMS is immediate and suits time-sensitive messages; email supports richer content and costs less per send. Most brands do best using both with clear roles.
Do I need consent for SMS marketing?
Yes. Marketing texts generally require explicit opt-in consent, and rules vary by country. Review the regulations and carrier guidelines that apply to you, and consult a professional if unsure.
Can I send the same message by SMS and email?
You can, but avoid duplicating every message. Use SMS for urgent or short prompts and email for detail, and coordinate timing so customers are not overloaded.
Tehseen Arbab
Retention and lifecycle marketer for DTC supplement and coffee brands. I led retention for a supplement brand whose monthly run-rate grew from about $500K to $700K, and I work in Klaviyo, Skio, Recharge, Meta Ads and Shopify.