Postscript

Postscript at a Glance

Postscript Overview

Postscript is an SMS marketing platform built exclusively for Shopify stores. Its entire product focus is SMS as a revenue channel, not an all-in-one email plus SMS platform. That focus lets it ship deeper SMS-specific features than the general marketing suites.

The platform is used by high-performing Shopify brands including True Classic, Thrive Causemetics, and The Sak, with vendor-reported outcomes of 34x return on investment on SMS spend and an average 20 percent revenue lift on AI beta features.

Postscript Capabilities and Named Features

Postscript covers the full SMS lifecycle: list growth, campaign sending, automations, response management, and analytics. The Visual Flow Builder ships built-in automation templates for cart and browse abandonment, welcome, upsell, and shipping notifications.

List growth is a real product strength. Popup Editor, CashBack, and Onsite Opt-in are named as differentiators, with vendor-reported 3x faster list growth than competing platforms and a 50 percent increase in conversion rate since introducing Onsite Opt-in.

The AI stack is Postscript AI: Brand Center trains the AI models on brand voice, offers, and product catalog. Infinity Testing runs hundreds of on-brand variants in a fraction of the time of manual A/B. Shopper is an always-on 1:1 shopping assistant answering questions and driving sales in real time.

Compliance is a real trust marker. Postscript maintains an in-house legal team dedicated to SMS compliance, which matters because SMS regulation (TCPA, CAN-SPAM, carrier-specific) is one of the biggest operational risks in the channel.

Named feature list

• Visual Flow Builder with built-in automation templates
• Cart and Browse Abandonment, Welcome, Upsell, Shipping automations
• Popup Editor for list growth
• CashBack for opt-in incentive
• Onsite Opt-in for higher conversion
• Checkout collection
• Custom contact card and dedicated toll-free number
• Advanced segmentation using Shopify data and third-party integrations
• Analytics and reports on subscribers, revenue, and messaging performance
• Response management for two-way SMS
• Custom attribution windows
• Custom brand voice via Brand Center
• Infinity Testing on Automations and Campaigns
• Shopper AI shopping assistant
• Enhanced Analytics on Professional tier
• API access on Professional tier
• Data Warehouse Push on Enterprise tier
• Onboarding Launch Specialist on Enterprise tier
• In-house SMS legal and compliance team
• CashBack add-on for margin protection
• Postscript Plus managed marketing service add-on

Postscript Pricing

Postscript publishes tiered pricing on the vendor pricing page. Starter is free with a USD 49 monthly minimum spend on messages. Growth is USD 100 per month, Professional is USD 500 per month, and Enterprise is Contact Sales. Per-message rates drop as brands move up the tiers.

Per-message rates below are Starter tier for context: SMS is USD 0.015 (as low as USD 0.009 on higher tiers) plus carrier fees. MMS is USD 0.045 (as low as USD 0.024) plus carrier fees. Average US carrier fees are USD 0.00418 for SMS and USD 0.00841 for MMS. Rates apply for US and Canada.

Postscript Pros

• SMS-only focus produces deeper platform capabilities than general email plus SMS suites.
• Vendor-reported 34x ROI on SMS spend and 22% online revenue attribution set a benchmark against competitors.
• List growth toolkit (Popup Editor, CashBack, Onsite Opt-in) is a real differentiator vs other SMS platforms.
• Postscript AI (Brand Center, Infinity Testing, Shopper) turns SMS into a conversational channel, not a batch send tool.
• In-house SMS legal team is a real compliance moat given TCPA and carrier risk.
• Named Shopify brand customers including True Classic and Thrive Causemetics support the enterprise ecommerce fit.

Postscript Cons and Trade-offs

• Shopify-only focus means the platform is not a fit for BigCommerce, WooCommerce, or non-Shopify carts.
• Starter tier per-message rate at USD 0.015 is higher than some competitors: brands should model at their expected volume.
• Higher tiers (Professional at USD 500 and Enterprise) are meaningful subscription cost commitments.
• AI features live in a separate Postscript AI Plan bundle, not baked into every tier.
• International reach beyond US and Canada requires additional rate confirmation with the vendor.

Postscript vs Alternatives

Who Should Choose Postscript

Postscript is a fit for a Shopify brand treating SMS as a real revenue channel, not a batch send tool. D2C brands with 5,000+ SMS subscribers and a plan to grow the list through popups, checkout, and onsite opt-in are the natural sweet spot. Shopify Plus brands running Postscript AI can push SMS to top-3 revenue channel status.

It is less of a fit for brands on BigCommerce, WooCommerce, or Salesforce Commerce Cloud, and for brands that want a single platform for email plus SMS: those buyers will lean Klaviyo or Attentive. Very-small brands sending occasional broadcast messages may not justify the Starter minimum spend.

Named Alternatives to Postscript

• Attentive. SMS-first plus email marketing platform for D2C and retail. Chosen when the buyer wants SMS plus email plus multi-cart-platform support.
• Klaviyo SMS. SMS as part of the Klaviyo email plus SMS platform. A better fit when the buyer wants unified email plus SMS attribution and analytics.
• Yotpo SMS. SMS marketing plus reviews platform. Preferred when the buyer already runs Yotpo for reviews and wants suite integration.
• Omnisend. SMS plus email plus web push for SMB ecommerce. Chosen when the buyer is on a lower budget and wants multi-channel from one platform.
• Textline. Business texting for support and sales. Preferred when the primary use case is two-way support conversations, not marketing sends.

Postscript Implementation and Deployment

Onboarding starts with the Shopify app install and toll-free number provisioning. Postscript ships built-in automation templates (Welcome, Cart Abandonment, Browse Abandonment) so brands can go live in days rather than weeks.

List growth is the second phase: Popup Editor, Onsite Opt-in, and CashBack are configured to grow the subscriber base at the vendor-reported 3x rate. Segmentation using Shopify data plus third-party integrations is set up so campaigns can be targeted rather than broadcast.

Postscript AI is enabled once the base workflow is stable and the AI has a data baseline to train on. Brand Center is trained on brand voice, offers, and product catalog. Infinity Testing replaces traditional A/B testing on the highest-volume campaigns. Shopper deploys as a 1:1 shopping assistant.

What Real Buyers Say About Postscript

The vendor publishes case studies and a Proof page dedicated to customer outcomes. Named customers include True Classic, Thrive Causemetics, and The Sak. See the vendor Postscript home page for the current customer logo strip and headline metrics.

Public commentary on ecommerce SMS forums positions Postscript as the leader for Shopify-only SMS, with Attentive as the multi-platform alternative. Buyers on Klaviyo email who want unified attribution often stay on Klaviyo SMS instead of splitting the stack.

The trade-off most reviewers name is the Shopify-only focus. Brands on multiple carts or planning a replatform should validate the timing before signing a Postscript contract.

Sources

• vendor website, Postscript Pricing page listing Starter, Growth USD 100, Professional USD 500, and Enterprise Contact Sales tiers
• vendor website, Postscript home page describing SMS-only focus, named customers, and headline outcomes

Frequently Asked Questions about Postscript

What is Postscript?

An SMS marketing platform built exclusively for Shopify stores. Covers campaigns, automations, list growth, response management, analytics, and AI-driven testing and conversational commerce.

Does Postscript work on platforms other than Shopify?

No. Postscript is Shopify-only. Brands on BigCommerce, WooCommerce, or Salesforce Commerce Cloud should evaluate Attentive or Klaviyo instead.

What are the per-message rates?

SMS is USD 0.015 (as low as USD 0.009 on higher tiers) plus average US carrier fee of USD 0.00418. MMS is USD 0.045 (as low as USD 0.024) plus average US carrier fee of USD 0.00841. Rates apply for US and Canada.

What is Postscript AI?

A bundle of AI products: Brand Center trains the models on brand voice. Infinity Testing runs hundreds of on-brand variants. Shopper is an always-on 1:1 shopping assistant. Available as a separate Postscript AI Plan.

Is there a free trial?

Yes. Postscript offers a free trial with a USD 100 credit that applies to message and carrier fees during the first 30 days.

Does Postscript handle SMS compliance?

Yes. Postscript maintains an in-house SMS legal team and calls out compliance as core to the product. This addresses TCPA and carrier-specific risk that is one of the biggest operational challenges in SMS marketing.

What integrations are available?

Postscript integrates with Shopify data plus a range of third-party ecommerce and marketing tools. Segmentation uses Shopify data plus integrations.

Where is Postscript headquartered?

Postscript is headquartered in Boston, Massachusetts, United States.

The Bottom Line on Postscript

Postscript is a fit for a Shopify brand treating SMS as a real revenue channel. The SMS-only focus produces deeper features than general email plus SMS suites, and the vendor-reported 34x ROI plus 22 percent online revenue attribution set a real benchmark against competitors.

The tradeoffs are Shopify-only coverage and the tier-based subscription cost. Brands on other carts will lean Attentive or Klaviyo. Brands that want unified email plus SMS attribution in one platform will still lean Klaviyo. Shopify-only brands willing to run two platforms get the deepest SMS capabilities from Postscript.

A useful evaluation is to install the Shopify app on the USD 100 free-trial credit, enable the Welcome and Cart Abandonment automations, and add Onsite Opt-in for list growth. That produces enough data in 30 days to model expected ROI at the brand actual list size and campaign volume.

Verified on 2026-08-01 against vendor website.

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