Email Marketing7.5/10

Postscript Review

Shopify stores that want SMS as a dedicated revenue channel, not just a bolt-on to email

Last updated 2026-04-02

Our verdict

The specialist SMS platform for Shopify. If SMS is a serious revenue channel for your store, Postscript's AI testing and conversational commerce features give it an edge over the SMS add-ons in Klaviyo and Omnisend.

What is Postscript?

Postscript is an SMS marketing platform built exclusively for Shopify. Unlike Klaviyo and Omnisend which treat SMS as an add-on to email, Postscript treats it as a dedicated revenue channel with its own AI tools, automation engine, and conversational commerce features. Over 18,000 Shopify brands use Postscript, including Dr. Squatch and Brooklinen, and the platform reports an average 34x ROI on SMS spend.

Key features

Infinity Testing is the standout feature. Instead of manually A/B testing two message variants, Postscript's AI generates and tests thousands of on-brand variations to find the highest performer. Shopper AI turns SMS into a two-way sales channel where customers can ask questions, get product recommendations, and complete purchases through a text conversation. The Brand Center trains the AI on your brand voice so automated messages sound like your team wrote them. Segmentation offers over 45 filters including Shopify order data, SMS engagement, product views, and integrations with Recharge, Yotpo, and Gorgias. Over 65 automation triggers cover everything from abandoned checkout to subscription renewals.

How it performs

Postscript delivers strong results when SMS is treated as a proper channel rather than an afterthought. The Infinity Testing feature is genuinely innovative and produces measurable improvements over manual A/B testing. The conversational AI works well for product recommendations and simple customer queries. The main consideration is cost. The free Starter plan charges $0.015 per SMS and $0.045 per MMS plus carrier fees. At high volume, this adds up quickly. The Growth plan at $25 per month reduces per-message rates. Revenue attribution in the native dashboard tends to overcount, so use a third-party tool like Triple Whale or Google Analytics for accurate numbers.

Who should use Postscript?

Postscript is the right choice if SMS is a meaningful part of your marketing strategy and you want a platform that treats it as a first-class channel. The AI features, particularly Infinity Testing and Shopper AI, go beyond what Klaviyo and Omnisend offer for SMS. If you only send occasional SMS campaigns alongside your email programme, the SMS features built into Klaviyo or Omnisend are probably sufficient. Postscript is Shopify-only and US/Canada-only, so if you sell internationally or on other platforms, it is not an option.

Pricing

Starter

Free

Pro

$25/mo

Free trial available

Score breakdown

Overall
7.5
Ease of use
8
Value
8
Shopify
10
Amazon
0

Pros

+Built exclusively for Shopify with deep integration
+AI-powered Infinity Testing across thousands of message variants
+Two-way conversational commerce with Shopper AI
+Free Starter plan with pay-per-message pricing

Cons

-Shopify only, no other platforms supported
-US and Canada only for SMS delivery
-Per-message costs add up at high volume
-Revenue attribution can overcount

Supported platforms

Shopify

Ready to try Postscript?

Shopify stores that want SMS as a dedicated revenue channel, not just a bolt-on to email