SMS Marketing for Shopify: When It Works and When It Backfires
We audit a lot of Shopify stores. And one of the patterns we see constantly is brands that have bolted on SMS as an afterthought, usually because a competitor was doing it or because an agency told them the channel has crazy ROI. Sometimes it does. Sometimes it torches their subscriber list in three months and they wonder why.
SMS is not email with a smaller screen. The rules are different, the expectations are different, and the margin for error is much smaller. Here is what we have learned from working with DTC brands who are getting it right and the ones who are getting it badly wrong.
Your Opt-In Strategy Determines Everything Downstream
The brands that struggle with SMS almost always have a broken opt-in strategy. They are collecting numbers through an aggressive pop-up that fires within five seconds of landing, offering a 10% discount in exchange for both an email and a phone number at the same time. Customers hand over the number to get the coupon. They were never actually interested in SMS communication. That is a list of hostages, not subscribers.
What works better is treating SMS and email as separate value propositions. If you are using Klaviyo for both channels, build separate flows and separate opt-in moments. The email pop-up can show early. The SMS opt-in should come later, either post-purchase, at checkout, or after someone has engaged with your brand at least once. ReCharge subscribers are a strong SMS audience because they have already committed to a recurring relationship with your brand. Someone who signed up for a subscription box is far more likely to want texts about their upcoming shipment than a first-time visitor who just wanted the discount code.
Compliance is not optional here. In the United States, the Telephone Consumer Protection Act requires explicit written consent for marketing messages. That means your opt-in copy needs to clearly state that the customer is agreeing to receive marketing texts, not just transactional ones. Tools like Attentive and Postscript handle a lot of this automatically, but you still need to review what the opt-in language actually says on your forms. We have audited stores where the checkbox copy was so vague that it would not hold up to scrutiny. That is legal exposure no one wants.
Transactional vs Promotional: The Line That Protects Your Metrics
Transactional messages have extremely high open rates and almost no negative response. Order confirmations, shipping updates, delivery notifications, and back-in-stock alerts for items someone specifically requested all perform well because customers are expecting and wanting that information. These should be running on every Shopify store that has SMS enabled. They are not glamorous but they build trust.
Promotional messages are where brands get into trouble. The temptation is to treat SMS like a high-urgency email blast. Flash sale today only. Last chance. We are dropping something big. If you send that kind of message twice a week, you will see unsubscribe rates climb fast. We have looked at Klaviyo dashboards where promotional SMS unsubscribes were running three to four times higher than email unsubscribes from the same campaign. The audience was smaller to begin with, so losing those subscribers hurt more.
A reasonable promotional cadence for most DTC brands is two to four sends per month maximum. Some categories can push that slightly, but you need to watch the data closely. Klaviyo shows you unsubscribe rate by message, and if a specific send spikes above 2%, that is a signal worth investigating before your next campaign.
The messages that perform best in promotional SMS are ones that have a genuinely time-sensitive reason to exist. A 24-hour sale. A product launch with limited inventory. An exclusive offer for subscribers that is not available elsewhere. If you can send the same message over email with the same urgency, you probably do not need to send it via SMS at all.
When SMS Outperforms Email and When It Does Not
SMS wins on speed and immediacy. Email open rates for most DTC brands hover between 20 and 40 percent, and a chunk of those opens happen hours or days after send. SMS open rates are reported as high as 95 to 98 percent, with most reads happening within minutes. For time-sensitive promotions, abandoned cart recovery within a tight window, or a restock alert where inventory will sell out, SMS is the right tool.
We have seen SMS abandoned cart sequences significantly outperform email sequences when set up correctly. The typical approach is to let the email flow run first, then trigger the SMS only if the customer has not converted after a set time window. Klaviyo makes this easy with conditional flow logic. You are not competing with your own email, you are using SMS as the closer.
SMS performs poorly when the brand has nothing urgent to say but sends anyway. We also see it underperform with certain product categories where customers want to research and deliberate before buying. High-ticket furniture, fine jewelry, or complex skincare routines do not convert well on a text message. The customer needs more than 160 characters to feel confident about a $400 purchase.
Analyzing which channel actually drove revenue requires some care. Last-click attribution will often credit SMS if a customer clicks a text link and buys the same day, but that customer may have been in the middle of an email flow or returning from organic search. We prefer to look at multi-touch attribution in GA4 and compare revenue per recipient across channels, not just revenue from clicks. The ROI on SMS can look extraordinary until you account for the fact that you are texting a smaller, self-selected audience that was already primed to buy.
Frequency, Fatigue, and the Metrics That Tell You You Are Overdoing It
The leading indicators of SMS fatigue are unsubscribe rate climbing above 2% per send, reply rate dropping toward zero, and click rate declining over successive campaigns. If you are inside Klaviyo and watching campaign performance over a rolling 90-day window, you will spot the trend before it becomes a crisis.
Frequency is not just about how often you send. It is about whether each send is earning its place in someone's message inbox. A useful test is to ask whether a customer who has been buying from you for a year would be annoyed or appreciative to receive this particular message. If the answer is annoyed, the message is probably not worth sending.
Suppression lists matter here as well. Customers who have not opened or clicked an SMS in 90 to 120 days should be suppressed from promotional sends. They are not engaged, and continuing to text them increases your opt-out rate without adding revenue. Klaviyo profiles store SMS engagement history and you can build segments around this quickly.
The brands that use SMS well treat it the same way they would treat texting a customer directly. You would not text someone three times a week trying to sell them something. The same restraint applies at scale.
If you want a second set of eyes on how your SMS setup connects to the rest of your conversion funnel, that is exactly what we cover in our conversion audit. We look at channel attribution, flow structure, opt-in mechanics, and where revenue is leaking across the whole store.