Is Klaviyo SMS good enough?

For 90% of eCommerce brands, yes. It handles campaigns, flows, A/B testing, compliance, and segmentation. The 10% who need Postscript are typically very high-volume SMS senders or brands needing advanced conversational commerce features.

Can we use Postscript with Klaviyo for email?

Yes, many brands do. But you lose the unified customer profile advantage. Cross-channel flows require integration workarounds. Data syncs instead of being natively unified. It works but adds complexity.

Which drives more SMS revenue?

In our experience, Klaviyo-unified SMS drives more total revenue because cross-channel flows (email + SMS together) outperform siloed SMS. Postscript might generate slightly more revenue from SMS alone, but total customer revenue (email + SMS combined) is higher with unified data.

Is Postscript SMS cheaper?

Slightly — per-message costs are marginally lower at higher volumes. But the revenue difference from unified data typically far exceeds the cost savings from cheaper per-message rates.

We are on Postscript now — should we switch?

If you are already on Klaviyo for email and Postscript for SMS, consider consolidating into Klaviyo SMS. The transition is straightforward and the unified data advantage pays off within 30-60 days. If your Postscript setup is generating strong results, it may not be urgent — but unified is objectively better long-term.

SMS Platform Comparison

The SMS debate is not about which tool sends better texts. It is about whether you want one customer profile or two.

Postscript is a phenomenal SMS marketing tool built specifically for Shopify. If SMS were your only channel, Postscript would be the obvious choice. Deeper SMS features, more flexible compliance tools, and purpose-built for text message marketing.

But SMS is never your only channel. You also send email. And when email and SMS live in different platforms, your customer data splits in two. One tool knows email behavior. The other knows SMS behavior. Neither sees the full picture. You cannot build a flow that sends an email, waits 24 hours, then sends an SMS if the email was not opened — without duct-taping two platforms together.

Klaviyo does both. One customer profile. One flow builder. Email and SMS in the same automation. That unified view is worth more than any individual SMS feature Postscript has.

150+

Brands Managed

Gold

Klaviyo Partner

25%

Revenue Lift (Unified SMS)

$23M+

Revenue Driven

We have managed accounts on both platforms. Postscript is genuinely impressive for standalone SMS — better keyword management, more flexible popup tools, and deeper SMS-specific features. But in every case we have seen, the revenue benefit of unified email + SMS data in Klaviyo outweighs those individual feature advantages. One customer view makes every message smarter.

Klaviyo vs Postscript — feature by feature

Feature	Klaviyo	Postscript
Email + SMS Unified?	Yes. Email and SMS in the same platform with one customer profile, shared segments, and unified automation flows.	SMS only. Email requires a separate platform (usually Klaviyo). Two customer profiles, two data sets, two tools to manage.
SMS Features	Solid SMS features: campaigns, flows, segments, A/B testing, and compliance tools. Covers 90% of what most brands need from SMS.	Best-in-class SMS features: advanced keyword automation, conversational SMS, AI-powered responses, deeper compliance tooling, and SMS-specific analytics.
Automation	Email and SMS in the same flow. Send an email, wait, check if opened, send SMS if not. True cross-channel automation without third-party connectors.	SMS-only flows. Cross-channel automation with email requires integration with your ESP, adding complexity and potential data sync delays.
Segmentation	Segments based on both email AND SMS behavior plus purchase data. A customer who ignores emails but reads texts gets different treatment automatically.	Segments based on SMS behavior and Shopify data. Cannot factor in email engagement without integration.
Pricing (SMS)	SMS pricing included in Klaviyo plans with per-message costs. Generally competitive but slightly higher per-message than Postscript at scale.	Competitive per-message pricing, especially at higher volumes. Slightly cheaper per message than Klaviyo at scale for SMS-heavy senders.
Shopify Integration	Deep Shopify integration shared between email and SMS. Unified customer profile with purchase, browse, and engagement data informing both channels.	Strong Shopify integration for SMS triggers and product data. Purpose-built for Shopify SMS use cases.
Compliance	TCPA compliance, consent management, and quiet hours built in. Covers requirements for US eCommerce SMS marketing.	More granular compliance controls, advanced opt-in flows, and deeper quiet hours customization. Better for brands with complex compliance needs.

Our recommendation

For 90% of Shopify brands: use Klaviyo for both email and SMS. The unified customer profile, shared segments, and cross-channel flows generate more revenue than any individual SMS feature Postscript offers. One platform knowing everything about your customers is more powerful than two platforms each knowing half.

Postscript makes sense if: you are already locked into a non-Klaviyo ESP, you send extremely high SMS volumes where per-message pricing matters significantly, or you need advanced conversational SMS features that Klaviyo does not offer yet.

Pick Klaviyo if...

Pick Klaviyo for both email and SMS if you want one platform, one customer profile, and unified cross-channel automation. This is the right choice for most Shopify brands.

Pick Postscript if...

Pick Postscript if you need best-in-class standalone SMS features, send very high SMS volume where per-message pricing matters, or use a non-Klaviyo ESP and need an SMS-specific tool.

Questions our best clients asked first

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