Postscript or Attentive is the SMS vendor question for DTC brands somewhere between their first SMS program and their first $5M in SMS-attributed revenue. Both vendors work. Both integrate with Shopify and Klaviyo. Both will ship you the compliance-ready opt-in flow and the campaign builder. The decision turns on pricing shape, not features.
The short version: small brands pick Postscript. Here's when that decision flips and what the migration cost is if you pick wrong.
The one-sentence answer
Small DTC brands (under roughly $3M in revenue, under ~150K SMS sends a month) should pick Postscript. Brands above that, especially ones already running enterprise Klaviyo or managing 500K+ subscribers, start making sense on Attentive.
For how this fits into the broader app-stack decision, see the Shopify app stack hub.
Where Postscript wins
Postscript is the DTC-small-brand SMS product. Built for Shopify from day one, friendlier onboarding, lower fixed monthly fees, and a UI that doesn't require a managed-services contract to operate.
Concretely:
- Lower floor. Monthly platform fee is small enough that a brand with 5K subscribers is not losing money just keeping the account open.
- Self-serve onboarding. A DTC operator can install, wire the Shopify triggers, and launch a welcome series in a weekend without a dedicated CSM.
- Klaviyo integration. Works well alongside Klaviyo email without fighting over attribution or consent state.
- Per-send pricing. Transparent, roughly predictable, scales with volume rather than contract tier.
It loses on:
- Deep automation. Once you need multi-step cross-channel orchestration with branch logic, Postscript starts feeling limiting.
- Enterprise account management. If you want a managed-services experience with dedicated strategy, Postscript is not that.
- Unit economics at very high volume. Above 200K+ sends a month, the per-send price starts favoring Attentive's volume contracts.
Where Attentive wins
Attentive is the enterprise SMS product, retrofit for mid-market DTC. More sophisticated tooling, more mature compliance infrastructure, pricier floor, and better unit economics at scale.
It wins on:
- Compliance at scale. TCPA litigation defense, carrier filtering, deliverability monitoring. This matters more than it sounds if you ever get a consumer protection complaint.
- Managed services. Strategy, template design, send-time optimization. Real humans engaged on your account.
- High-volume per-send pricing. Contract-based, better rates once you cross ~150K sends per month.
- Cross-channel orchestration. Email + SMS + MMS in one flow with shared attribution. If you're running a big lifecycle program, this is useful.
It loses on:
- The floor. The platform fee and the minimum contract make it uneconomical for a brand at sub-$2M in revenue.
- Speed to launch. Onboarding typically runs 4 to 8 weeks. A DTC founder doing this themselves gets impatient.
- Lock-in feel. Contract terms lean in favor of Attentive. Exit is possible but less friendly than Postscript.
“Small brand, small vendor. Big brand, big vendor. The match of vendor size to brand size matters more than the feature comparison.
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Pricing shape: what actually scales
The single most useful thing to do before picking is to project your SMS cost at 2x your current subscriber base and send volume. Then do the same at 5x. Three patterns show up:
- Small-brand curve. Postscript stays cheaper. Attentive never crosses over.
- Crossover curve. Postscript wins today, Attentive wins in 18 months. Pick Postscript now, plan the migration when volume crosses the threshold.
- Enterprise curve. Attentive is already cheaper, or the managed services pay back immediately.
Pattern 2 is the common trap. Brands sign with Attentive because a friend said they should "pick the enterprise option," eat a $3K-5K per month platform fee for a year, and never actually hit the volume where Attentive is economical.
Compliance is not the same as features
Both vendors ship TCPA-compliant opt-in flows out of the box. Both do carrier-level spam filtering. Where they differ is in what happens when something goes wrong.
- Postscript's compliance story is documentation, automatic keyword handling, and a small legal team you can contact.
- Attentive's compliance story is all of that plus a full deliverability-engineering team, carrier relationships, and litigation defense support.
For a small brand that isn't a TCPA enforcement target, Postscript's compliance is sufficient. For a brand with 500K+ subscribers sending daily campaigns, Attentive's infrastructure is worth paying for.
Klaviyo SMS, the third option
The third option worth naming is Klaviyo SMS. If you already run Klaviyo for email, Klaviyo SMS is in the same UI with the same customer profile and attribution model. That's meaningful. The feature depth is less than either Postscript or Attentive at this point, but the consolidation value is real.
For small brands where SMS is a side channel (under ~20 percent of lifecycle revenue), Klaviyo SMS is often the right answer. For brands where SMS is a serious primary channel, a dedicated vendor still wins. The SMS vs email decision matrix for DTC has the breakdown.
If you're evaluating Klaviyo versus Omnisend for email while you're at it, see Klaviyo or Omnisend for a sub-500 SKU catalog.
Migration cost if you pick wrong
Migrating between SMS vendors is relatively painless compared with support-inbox migration. The subscriber list moves cleanly (with re-consent depending on terms). The flows are mostly portable at the logic level. The main costs:
- Re-consent. Depending on your vendor contract, you may need to re-opt-in subscribers when moving platforms. This almost always costs you 10 to 20 percent of your list.
- Flow rebuild. A month of work rebuilding flows and templates.
- Attribution reset. Historical SMS attribution lives with the vendor you used. If you leave, you lose the historical reporting.
Realistic migration cost is 3 to 6 weeks of wall-clock time and $5K to $15K in fully-loaded work. Manageable, but not free.
For the full stack context and what else you should be auditing at the same time, see the DTC Stack Audit product.
Is Postscript or Attentive better for a DTC brand under $3M in revenue?
Postscript. The monthly floor is lower, onboarding is self-serve, and the per-send pricing scales gracefully at low to mid volume. Attentive's platform fee and minimum contract make it uneconomical for brands at this revenue band unless you already have enterprise contracts with adjacent vendors.
At what SMS volume does Attentive start winning on pricing?
Roughly 150K to 200K sends per month is the illustrative crossover in most contracts. Actual crossover depends on your Attentive contract terms (enterprise rates are negotiable) and your Postscript per-send price tier. Model both curves at your current volume and at 2x before deciding.
Can I use Klaviyo SMS instead of a dedicated SMS vendor?
Yes for brands where SMS is a side channel under about 20 percent of lifecycle revenue. Klaviyo SMS lives in the same UI as Klaviyo email, which is a real consolidation win. For brands running SMS as a primary channel with daily campaigns and subscriber lists over 100K, a dedicated vendor still has deeper tooling.
What's the TCPA risk of DIY compliance on Postscript?
Low for brands doing standard Shopify DTC opt-in (checkout checkbox, exit-intent popup with clear consent language, SMS-specific Terms linked). The risk increases if you buy lists, send to unconsented numbers, or ignore opt-out requests. For most DTC brands running a normal SMS program, Postscript's built-in compliance is sufficient.
How hard is it to migrate from Attentive back to Postscript?
Not hard from a technical standpoint. 3 to 6 weeks of wall-clock time and roughly $5K to $15K in fully-loaded cost. The friction is contract exit terms (Attentive contracts are annual) and re-consent of subscribers under some terms. Plan the migration for a contract renewal window and budget for 10 to 20 percent list attrition at re-consent.
Sources and specifics
- Pricing and feature comparisons reflect publicly available plans and observed contract behavior as of April 2026.
- The crossover volume is illustrative; actual contracts vary by negotiation and usage profile.
- Compliance guidance is general. For litigation-specific risk, consult TCPA counsel.
- For broader app-stack context, see the Shopify app stack hub and the DTC Stack Audit product.