Retention apps are the only category on the App Store where the tool is routinely blamed for a result the setup caused. A brand on Klaviyo with a 9% repeat rate and a brand on Klaviyo with a 34% repeat rate are running the same software. The difference is whether the flows fire on the store’s own events, whether the timing matches how the product is used, and whether anyone reads the cohort report instead of the app’s attributed revenue.
This comparison is written from stores we run: True Glory Hair, where retention on Attentive lifted the repeat purchase rate 27%, and CocoLash, on Klaviyo with Subscribe & Save from launch. Seven apps across email, SMS and loyalty, compared on the flows that bring customers back, and then the wiring that makes any of them work.
Summary
- Klaviyo: the default for email-first brands; one tool for email, SMS, segmentation and the data model behind them.
- Attentive: SMS-first, enterprise-grade compliance and two-way messaging; what True Glory Hair runs.
- Postscript: SMS built for Shopify at mid-market scale.
- Omnisend: email and SMS bundled at a lower price for smaller stores.
- Smile.io: the quickest loyalty start — points, referrals, VIP tiers.
- LoyaltyLion: loyalty for mid-market and Plus stores that want the programme in the theme.
- Rivo: loyalty and referrals with an API, built for Plus and custom storefronts.
Retention is a wiring problem
Every tool below receives the same raw material from Shopify: orders, customers, products, and — with the app’s storefront script — browse and cart activity. What the store sends decides what the flows can do. The events that matter:
- Placed order, with the line items, so the post-purchase flow can be product-specific.
- Fulfilled and delivered, so “how to use it” lands when the box does.
- Viewed product and added to cart, for the abandonment flows.
- Subscription started, skipped, cancelled, payment failed — from the subscription app, if you run one.
- Review left, from the review app, so the flow can thank and segment.
- Loyalty points earned and tier changed, from the loyalty app.
On True Glory Hair the purchase and browse events flow out of the Shopify Plus store into Attentive; the win-back and replenishment offers flow back in; and the repeat purchase rate is the number the programme is judged on. That is the whole architecture. Our retention marketing engagements are mostly building it.
Email and SMS
1. Klaviyo
Klaviyo is where most Shopify brands start and many stay: email and SMS in one account, segmentation on any property or event, a flow builder that handles branching and A/B splits, predictive analytics (expected next order date, churn risk, lifetime value) that are genuinely useful for timing, and integrations with nearly every review, subscription and loyalty app. Pricing is by active profiles and SMS volume, and it climbs — the list needs pruning as a matter of routine. Best for email-first brands, content-heavy programmes and catalogues where product-specific flows matter; CocoLash runs its flows here from launch.
2. Attentive
Attentive is SMS-first and built for scale: list growth tooling, compliance handled properly (consent capture, quiet hours, carrier rules), two-way conversational messaging, and email added alongside. It is an enterprise contract rather than a self-serve plan, which is the trade-off. For a brand where SMS is the primary channel and the list is large — hair, beauty, fashion drops — it is the strongest option on the list, and it is what carried True Glory Hair’s 27% lift.
3. Postscript
Postscript is SMS built specifically for Shopify at mid-market scale: flows on Shopify events, keyword opt-ins, a self-serve plan that grows with volume, and conversational tooling. The natural choice for a store that runs email in Klaviyo and wants a dedicated SMS tool without an enterprise contract.
4. Omnisend
Omnisend bundles email and SMS at a lower price point with pre-built Shopify flows, and is the right choice for a smaller store that wants the standard five flows running this week without a data model to think about. It has less depth in segmentation and integrations than Klaviyo, which most stores under a few thousand customers will not miss.
Loyalty
5. Smile.io
Smile.io is the fastest way to a working loyalty programme: points for purchases and actions, referrals, VIP tiers, a launcher widget, and a free tier. The widget is the limitation — it sits on top of the store rather than inside it — and the programme logic is simpler than the two below.
6. LoyaltyLion
LoyaltyLion is built for mid-market and Plus stores that want loyalty in the theme: points and tiers on the product page and in the account, integrations with Klaviyo and the review apps, and the reporting to see whether the programme changes behaviour or just discounts it.
7. Rivo
Rivo is the developer-friendly loyalty option: an API and theme blocks that let a custom or headless storefront render the programme natively, referrals, and Plus-oriented features like points on subscription renewals. The right pick when the storefront is custom and the widget approach is not acceptable.
Quick comparison
| App | Type | Pricing model | Strength | Best for |
|---|---|---|---|---|
| Klaviyo | Email + SMS | By profiles and SMS volume | Segmentation, predictive timing, integrations | Email-first brands, product-specific flows |
| Attentive | SMS (+ email) | Enterprise contract | Compliance, two-way, scale | SMS-first brands with large lists |
| Postscript | SMS | Self-serve by volume | Shopify-native SMS | Klaviyo-for-email stores adding SMS |
| Omnisend | Email + SMS | Lower, by contacts | Pre-built flows, price | Smaller stores |
| Smile.io | Loyalty | Free tier, then by orders | Speed to launch | First loyalty programme |
| LoyaltyLion | Loyalty | By orders / tier | In-theme programme, reporting | Mid-market and Plus |
| Rivo | Loyalty + referrals | By tier | API, theme blocks | Custom and headless storefronts |
The five flows every store needs
- Post-purchase. How to use it, how to care for it, when it will need replacing — timed to the product, not a generic thank-you. On a wig brand: install, care, when to book the next install.
- Replenishment. Lands before the product runs out, with the reorder one tap away. The timing comes from the product’s use cycle, and Klaviyo’s expected-next-order date is a reasonable default when you do not know it.
- Browse and cart abandonment. Show what she looked at, say which one to pick for what, and do not lead with a discount.
- Win-back. At 60 and 120 days past the expected reorder, with the offer that matches what she bought — not a site-wide code.
- VIP. The top decile gets early access, not discounts. Loyalty tier changes are the trigger.
Loyalty: when it works and when it is just margin
Points work in replenishment categories — beauty, supplements, coffee, pet — where a second order is the natural next step and the programme gives it a reason. In a one-purchase category, a points programme mostly moves margin from orders that would have happened anyway. The test: build the programme, then compare the 90-day repeat curve for members and non-members from the same first-order cohort. If the curves are the same, the programme is a discount.
Measuring it honestly
The email and SMS tools report attributed revenue with generous windows; the store’s own reports do not. The number to run the programme on is the repeat purchase rate and the 90-day repeat curve by first-product cohort, from Shopify. If the tool claims more revenue than repeat customers actually spent, the attribution window is the reason. True Glory Hair’s 27% is measured on the store, which is the only place it counts.
If the flows exist and the number is not moving, the free CRO audit covers the retention path — events, timing, offers, the subscription portal — in the same 48 hours as the storefront, and the lifecycle marketing retainer is the monthly version. For the platform decision alone, the email marketing comparison goes deeper on Klaviyo versus the rest.
FAQ
Klaviyo or Attentive for a Shopify store?
Klaviyo when email is the primary channel and you want one tool for email, SMS and segmentation. Attentive when SMS is the primary channel, the list is large and you want its compliance and two-way messaging tooling. True Glory Hair runs Attentive and lifted its repeat purchase rate 27%; CocoLash runs Klaviyo. The wiring to store events matters more than the choice.
Do loyalty programmes work for Shopify stores?
For replenishment categories, yes — points and a VIP tier give a second-order reason that a discount code does not. For a one-purchase category they mostly move margin. Smile.io for a quick start, LoyaltyLion and Rivo for a Plus store that wants the programme in the theme and the checkout.
What retention flows should every Shopify store have?
Post-purchase (how to use, when to reorder), replenishment timed to the product’s use cycle, browse and cart abandonment, win-back at 60 and 120 days, and a VIP or loyalty flow for the top decile. Five flows, all triggered by the store’s own events.
How do I measure retention on Shopify?
Repeat purchase rate and the 90-day repeat curve by first-product cohort, from Shopify’s own reports, not the email tool’s attributed revenue. If the flow tool claims more revenue than the store’s repeat customers actually spent, the attribution window is too generous.
