Pick Attentive if SMS is a channel with its own team and budget and you want the vendor to run part of the program for you. Pick Postscript if you want a Shopify-first company that does SMS and nothing else, and you will judge it on SMS revenue alone. Pick Klaviyo SMS if your email already lives in Klaviyo and one customer profile, one flow builder and one bill matter more to you than the deepest SMS feature set.
What each one is built for
All three send texts from a Shopify store. The difference is what sits around the send: who the product is designed for, what the vendor wants to sell you next, and how much of the work you do yourself.
 Attentive |  Postscript |  Klaviyo SMS | |
|---|---|---|---|
| Built for | Large brands running SMS as its own channel | Shopify brands that want an SMS specialist | Brands already running email on Klaviyo |
| What else it sells | Email, and managed services on top | Conversational selling over text | Email, reviews, customer data |
| Where it is strongest | List growth at scale and a hands-on account team | Shopify-native flows and a narrow product focus | One profile shared by email and SMS |
| Most common reason brands leave | Cost, and a roadmap that drifts away from SMS | Account support that varies by rep | SMS features that trail the specialists |
| Typical switch | To Postscript, or into Klaviyo to consolidate | Into Klaviyo to consolidate | Out to a specialist once SMS revenue is large |
Attentive: the default at the top of the market
Attentive is the platform most large Shopify Plus brands arrive with. Its pitch is list growth and a managed program: an account team that helps plan campaigns and a sign-up unit that is hard to match at high traffic.
Two complaints come up again and again. The first is price, which is easy to justify at the top of the market and hard to justify once SMS revenue flattens. The second is focus. Since Attentive added email, some SMS-first teams feel the product has spread itself across features they never asked for.
Postscript: the specialist
Postscript was built for Shopify and only does SMS. That focus is the reason teams switch to it: the roadmap is about texting customers, and the product assumes Shopify data from day one. Its newer conversational tools answer shopper questions over text, which suits brands whose customers ask before they buy.
The weak spot is the thing a specialist should be best at. Brands that love the product sometimes describe their account rep as the difference between a great year and an average one. If you rely on your rep for strategy, ask to meet them before you sign.
Klaviyo SMS: the consolidation play
Klaviyo sells SMS as part of the platform most Shopify brands already use for email. The case for it is simple: one customer profile, one segment builder, one set of flows, and pricing that gets better when you buy both channels.
That pricing is the pull, and it works in both directions. Brands consolidate into Klaviyo to cut a vendor, and brands with serious SMS revenue move out again when they want features Klaviyo does not prioritise. If SMS is a small share of your revenue today, consolidation is usually the right call. If it is a large share, compare the specialists before you move.
How to decide
Whichever you pick, migrate your subscribers with their consent records intact, and run the old and new platforms side by side for a few weeks. List loss during a switch is the cost nobody quotes you.
Who runs what
We visit Shopify storefronts and record the apps we can see running on them. ButcherBox runs Klaviyo on its storefront, for example. Every brand page on dtcmvp.com lists what we saw and how we count.
Questions people ask
Is Attentive or Postscript better for a Shopify brand?
Attentive suits large brands that want a managed program and are willing to pay for it. Postscript suits Shopify brands that want an SMS-only vendor and a product built around Shopify data. Run the same test on both before deciding.
Should I use Klaviyo for SMS if I already use it for email?
Usually yes when SMS is a small share of revenue, because one profile and bundled pricing save time and money. When SMS is a large revenue channel, compare the specialists first.
What is the hidden cost of switching SMS platforms?
Subscriber loss. Move consent records with the list and run both platforms in parallel for a few weeks so nobody falls through the gap.
