Postscript and Attentive are the SMS duopoly on Shopify Plus. Both work; neither is broken; the choice is about which side of a real trade-off you want to be on. At $5M–$25M GMV without a dedicated SMS marketer, Postscript wins on operator experience and Klaviyo integration depth. At $25M+ with a 2-plus-person SMS team, Attentive wins on AI message generation, advanced testing, and the enterprise-grade reporting that a serious SMS program demands.
The pure feature gap is narrower than it was three years ago. Both ship the seven core SMS programs (welcome, abandoned checkout, browse abandonment, post-purchase, win-back, replenishment, broadcast). Both integrate with Klaviyo, Recharge, Smartrr, the major loyalty apps, and Shopify natively. The differentiation lives in operator support, AI tooling, and enterprise governance — areas where the two platforms have made different long-term bets.
Side-by-side
| Axis | Shopify Plus | Attentive |
|---|---|---|
| Cost at $10M GMV | Postscript: $4K–$10K/month, predictable volume-based pricing, month-to-month available. | Attentive: similar volume math but annual contracts often start at $25K/year minimum. |
| Operator support | Postscript: rep-led account management, fast onboarding, transparent escalation paths. Built for founder/small-team operators. | Attentive: enterprise CSM model, structured QBRs, designed for marketing teams of 3-plus. |
| AI features | Postscript: AI-assisted copy generation, send-time optimization. Functional, not the platform’s differentiator. | Attentive: deeper AI tooling for message generation, audience targeting, and creative iteration. The platform’s strongest moat. |
| Klaviyo integration depth | Postscript: deepest in the SMS category. Every subscription / loyalty / Shopify event flows both directions. | Attentive: very strong but trails Postscript’s trigger depth slightly. |
| Agency ecosystem | Postscript: large network of Postscript-fluent agencies and freelancers; easy to hire help. | Attentive: smaller but more enterprise-leaning agency network; harder to hire fractional help under $20M. |
| Enterprise reporting | Postscript: solid reporting; cohort analysis works; not enterprise-grade. | Attentive: best-in-category reporting; multi-brand support; serious governance features. |
| Migration cost | Postscript-to-Attentive migration: $15K–$40K and 4–8 weeks. Subscriber list migrates cleanly; flow rebuild is the cost. | Same in reverse; Attentive-to-Postscript migration is rarer but mechanically similar. |
Migration path
- Launch on Postscript at $5M–$15M GMV; the operator experience and pricing flexibility fit the band best.
- Reassess at $20M GMV when the SMS team grows past 1 dedicated marketer. If AI-led content scale or enterprise governance is the next program priority, plan an Attentive migration.
- If you stay on Postscript through $25M+, expect to negotiate custom contract terms; Postscript supports this but it isn’t the platform’s default sales motion.
- Migration project: $15K–$40K all-in (platform setup, flow rebuild, subscriber list migration, Klaviyo re-integration). 4–8 weeks end-to-end.
- Post-migration: expect a 1–2 week dip in attributed SMS revenue while the new flows ramp. Recover within 30 days.