Table of Contents
Why Klaviyo Is the Best Email Choice for Shopify
When we sold Superbon to SPRiNG in 2022, one of the things that impressed the buyers most was our email machine. Not our product catalog, not our design, but our Klaviyo setup, which generated 32% of our monthly revenue. That figure may seem optimistic, but it simply reflects the reality of a well-executed email strategy.
Email marketing remains the #1 converting channel for e-commerce in 2025, with an average ROI of 36:1 according to the latest industry studies. For every euro invested in Klaviyo, well-optimized e-commerce brands get back 36 euros on average. It is mathematical, measurable, and above all, it is a channel you own, unlike Meta or Google audiences.
Why Klaviyo specifically for Shopify? Because the native integration is so deep that it turns your Shopify database into a real behavioral goldmine. Where Mailchimp gives you access to emails and first names, Klaviyo automatically syncs the full purchase history, browsing behavior, products viewed, cart abandonments, Customer Lifetime Value, and even the custom metafields you have created. Everything you need to know about Klaviyo comes down to this unique ability to turn Shopify data into personalized emails that convert.
Compared with Omnisend or ActiveCampaign, Klaviyo largely dominates the Shopify ecosystem for one simple reason: the tool was designed for e-commerce from the start, not adapted after the fact. On Cabania, where we generate over €100k in monthly revenue, Klaviyo accounts for 28 to 35% of revenue depending on the month. If you are launching your Shopify store, integrating Klaviyo from day one is not a luxury, it is a strategic foundation.
Klaviyo × Shopify Integration: Complete Setup
Native Installation in 5 Minutes
The beauty of the Klaviyo-Shopify integration is its initial simplicity. From the Shopify App Store, you install the app in one click, grant the sync permissions, and in under 5 minutes your Klaviyo account starts ingesting all of your store's data. No developer needed, no complex configuration for the basic setup.
But be careful: "installing" is not "optimizing". Check out our step-by-step setup tutorial to understand the subtleties that make the difference between a basic setup and a powerhouse email machine.
Customer Data Synchronization
This is where Klaviyo shows its full power. As soon as it is installed, the tool automatically starts syncing each customer's full purchase history: who bought what, when, for how much, and how many times. Above all, Klaviyo tracks your visitors' browsing behavior in real time.
A visitor views three products in your "face care" category without adding anything to their cart? Klaviyo knows, and can trigger a browse abandonment email 24 hours later featuring exactly those three products. A customer adds a product to their cart but abandons the funnel? The "added to cart" event is captured instantly, enabling a first automatic reminder email in under an hour.
Custom properties are synced too: automatically calculated Customer Lifetime Value, Shopify tags you have created (VIP, Wholesaler, Influencer), and even metafields if you have configured them. On Cabania, we use metafields to track configuration preferences for cabin beds, which lets us send ultra-personalized emails about accessories compatible with the exact configuration ordered.
Advanced Tracking Setup
Klaviyo's "Active on Site" tracking is an often underused game-changer. Once enabled, it captures browsing behavior even for unidentified visitors (via cookie), then reconciles that data as soon as they sign up or place an order. The result: you can send a welcome email that mentions the three products the person viewed before they even signed up.
"Back in Stock" alerts also deserve special attention. On our brands, this flow consistently generates conversion rates between 15 and 30%, well above the email average. Setup is done product by product in Klaviyo, with an automatic signup form that appears when a product is out of stock.
For cart abandonment, Shopify already sends a native email if you enable it in the settings, but Klaviyo tracking is far more powerful: it lets you build multi-email sequences with dynamic personalization, A/B testing, and fine-grained segmentation based on cart value or the products involved.
Essential First Settings
Double opt-in or single opt-in? In France, this is a sensitive question because of the GDPR. At Stellar Projects, we always recommend double opt-in for two reasons: guaranteed legal compliance and a higher-quality list. Yes, you lose 20 to 30% of signups between the first click and the email confirmation, but the contacts who confirm are genuinely engaged and your deliverability stays excellent.
Basic segmentation should be set up from day one. At a minimum: separate newsletter subscribers from paying customers, and create segments by language if you operate in several languages. When you migrate to Shopify, it is also the ideal time to cleanly restructure your Klaviyo database and start again on healthy foundations.
The 7 Essential Email Automations
1. Welcome Series: The First 3 Emails That Lay the Groundwork
The welcome series is your first impression, and it consistently generates the best open rates in your email program: expect a 50-60% open rate on the first email, sometimes even 70% if your lead magnet is strong.
The classic 3-email structure works remarkably well. Email 1, sent immediately after signup: a warm welcome, a quick introduction to the brand, and a 10% discount code to turn interest into a first order. At Superbon, this first email alone generated 8% direct conversion.
Email 2 arrives 2-3 days later: this is where you tell your story, why you created the brand, what sets you apart, and you showcase your bestsellers with social proof (customer reviews, number of sales). This is your storytelling moment, the one where you build an emotional connection.
Email 3 on day 5 or day 7: create urgency and make a final push. The discount code expires in 48 hours, your customers love a particular product (stronger social proof), and you offer a user guide or tips to get started. This is your last opportunity to convert before the prospect goes "cold".
2. Cart Abandonment: Recovering 15-25% of Lost Revenue
Cart abandonment is the most profitable flow in any Klaviyo program, period. On our brands, it accounts for 12 to 18% of total email revenue. Timing is critical: first email 1 hour after abandonment (gentle reminder, "you forgot something"), second email at 24 hours (added urgency, "these products are selling fast"), third at 48 hours (incentive if needed, or stronger social proof).
A fourth email at 72 hours is optional depending on your sector. On Cabania, where the average order value exceeds €800, we always use it because the decision cycle is longer. At Superbon, with an average order value of €45, three emails were more than enough.
The progressive incentive technique works well: no discount in the first two emails (many people come back on their own), then 10% off in the third only if the cart exceeds a certain amount. This avoids conditioning your customers to always wait for a promotion.
Personalize as much as possible: show the exact images of the abandoned products, use the first name, mention if stock is limited (real urgency, not artificial), and add customer reviews specific to those products. A generic "come back and complete your order" template converts 2-3 times less than a truly personalized email.
To go further on sequence architecture, pairing with SMS and retargeting, and recovery benchmarks by sector, see our complete method for recovering abandoned carts.
3. Post-Purchase and Upsell: Maximizing Lifetime Value
The first post-purchase email goes out immediately after the order: a warm thank-you, an order summary and a tracking link. Nothing revolutionary, but it is a moment of positive emotion not to be neglected. Typical open rate: 60-70%.
The smart cross-sell email arrives 7 days after delivery (give the customer time to receive and try the product). Klaviyo excels here: you can use AI recommendation blocks that automatically suggest complementary products bought by other customers who ordered the same item. At Superbon, our face serum consistently triggered a recommendation for the moisturizer, with a 12% conversion rate on that email.
The customer review request on day 14 is crucial for your social proof and your SEO. Integrate Yotpo or Judge.me with Klaviyo, and the flow triggers automatically with a direct link to the review form. Offering a small incentive (50 loyalty points, entry into a prize draw) significantly boosts the response rate.
The repeat purchase email on day 30-45 (adjust to your product's consumption cycle) is a smart reminder: "time to restock your serum", with an automatic calculation based on product size and average usage. Add a subscription option (via ReCharge) to turn a one-off purchase into recurring revenue.
4. Browse Abandonment: Capturing Intent Before the Cart
Browse abandonment is the often-overlooked flow that can generate 3 to 5% in additional revenue. The trigger: a visitor views 2 or more products without adding anything to their cart. The email goes out 24 hours after the visit (not too early so as not to be intrusive, not too late so the interest is still there).
Personalization is essential: show exactly the products viewed with their images, prices and a few customer reviews. Add 2-3 similar or complementary products to broaden interest. On Cabania, this flow converts at 2.5% on average, or about €3,000 in monthly revenue for an automated email running in the background.
5. Back in Stock: The Flow with Exceptional Conversion Rates
If one flow deserves your priority attention after cart abandonment, it is Back in Stock. Why? Because a customer who signs up to be notified of a restock is showing very strong purchase intent. They have already made the effort to leave their email specifically for that product.
The result: conversion rates between 15 and 30% depending on the sector, whereas a standard email converts at 1-2%. At Superbon, our bestseller, out of stock for 3 weeks, generated 847 Back in Stock signups. When we restocked, the automated flow converted 223 orders in 48 hours. An instant and massive ROI.
Setup in Klaviyo is simple: create a flow with the "Subscribed to Back in Stock" trigger, wait until the product is available again (the condition is checked automatically via the Shopify sync), and send the notification immediately. Add a sense of real urgency: "Only 50 units available" if that is truly the case.
6. Reactivating Inactive Customers: Win-Back Campaigns
Segmenting by length of inactivity is the foundation of reactivation campaigns. Create three segments: inactive for 60 days, 90 days and 180 days. For each segment, the approach and the incentive are adjusted.
At 60 days, a simple reminder is often enough: "it's been a while", show your new arrivals, mention that you are thinking of them. No discount needed. At 90 days, add a light incentive (10% off or free shipping). At 180 days, bring out the big guns: 20% off, an exclusive offer or a special bundle. At this stage, you are not recovering margin, you are recovering the customer.
On Cabania, our "inactive 180+ days" segment is paradoxically a real goldmine: these are former buyers who have already spent €850 on average (high average order value). Reactivating just 5% of them per quarter represents €15k to €20k in additional revenue with a single well-designed email.
7. VIP Customer Winback: Special Treatment for High Value
Not all customers are equal, and your VIPs deserve differentiated treatment. Create a "High Value Customers" segment based on CLV (Customer Lifetime Value): for example, everyone who has spent more than €500 over the last 12 months.
For this segment, offers are exclusive and personalized: early access to new products, VIP discounts not shared with the rest of the list, invitations to private events or webinars, a direct line to the founder. At Stellar Projects, we apply this principle to our own clients: those who have generated more than €50k in projects benefit from a priority hotline and complimentary strategic advice.
Integrating a loyalty program (Smile.io, LoyaltyLion) with Klaviyo lets you automatically display the customer's points balance in every email, creating a constant reminder of the value they have accumulated and encouraging spending. Strategies to increase your sales with email marketing all rely on this kind of smart personalization based on customer value.
Email marketing is one of the 5 most powerful off-site levers for increasing a Shopify store's conversion rate. To place Klaviyo within a complete conversion strategy that also covers the on-site experience (homepage, product, checkout, mobile) and buying psychology, see our guide to the 25 levers for optimizing your Shopify conversion rate, with benchmarks by sector.
Advanced Segmentation: Maximizing Relevance
The RFM Method: Recency, Frequency, Monetary
RFM segmentation is the holy grail of e-commerce email personalization. It combines three dimensions: when the customer last bought (Recency), how many times they have bought (Frequency), and how much they have spent (Monetary). This creates ultra-precise behavioral segments that let you fine-tune both message and offer.
Your "Champions" are customers who bought recently, buy often and spend a lot. This is your VIP segment, which should receive exclusive offers, not generic promotions that would devalue their status. At Superbon, this segment represented only 8% of the list but 34% of email revenue.
"Loyal" customers buy frequently with decent order values, but have not ordered recently. Be careful: this segment is at risk of churn. Reactivate them with a personal message, an emotional reminder of why they loved your products, and a targeted offer if needed.
"At risk" customers have not bought for X days (to be defined based on your typical product cycle). For Superbon, with cosmetics lasting 2-3 months, "at risk" meant 90 days of inactivity. For Cabania, where a cabin bed is a one-time purchase, it is more like 180 days without interaction (email open, site visit).
"Lost" customers have gone more than 180 days with no activity at all. Before excluding them for good (sunset policy), try one last aggressive win-back campaign. If there is no response, remove them: they drag down your open rates, damage your sender reputation and cost you money (Klaviyo bills by number of contacts).
Behavioral and Predictive Segments
Beyond RFM, segment by product category purchased. A customer who had only bought face care at Superbon received different emails from a customer focused on body or hair. It seems obvious, but many brands still send the same email to their entire list.
The acquisition source (Meta, Google, organic, affiliate) also influences behavior and expectations. Customers who came from Meta generally respond better to striking visuals and short offers, while those who came from Google search are more receptive to educational content and product comparisons.
Device (mobile vs. desktop) radically changes how your emails are consumed. 70% of opens now happen on mobile, but desktop conversions often remain higher (higher average order value, smoother checkout on a large screen). Adapt your templates accordingly: on mobile, a single, highly visible CTA; on desktop, you can afford more richness.
Klaviyo's predictive segments use machine learning to estimate each customer's "Predicted Next Order Date". On Cabania, we use this data to trigger accessory cross-sell emails exactly when the algorithm predicts the customer is ready to buy again. Open rate: 42%, click rate: 8.3%, well above our campaign averages.
A concrete example from our cosmetics experience at Superbon: we segmented our list into 3 main profiles (Minimalist Routine, Skincare Addict, Curious Explorer) based on the number of products purchased and the variety of categories explored. Each profile received a different email calendar and different product recommendations. The result: +18% repeat purchase rate over 6 months compared with the previous one-size-fits-all approach.
Design and Content: Templates That Convert
2025 Email Design Principles
Email design has changed enormously in recent years, and 2025 continues to accentuate certain trends. Mobile-first is no longer optional but mandatory: 70% of opens happen on smartphones, and an email that is not optimized for mobile gets deleted immediately.
The visual hierarchy must be crystal clear: logo at the top, a clear and impactful headline, a dominant product visual, and a highly visible CTA above the fold. On mobile, users do not always scroll, so the essentials must be visible immediately. Test your templates on iPhone and Android, as rendering sometimes varies significantly.
CTAs deserve special attention. A button that is too small on mobile is frustrating, one that is too big feels aggressive. Our sweet spot at Stellar Projects: a minimum height of 44-48px on mobile, a color that contrasts with the background, and action-oriented text ("Discover now" rather than "Click here"). Always A/B test the color: at Superbon, a powder pink CTA converted 23% better than a black CTA, in keeping with the brand identity.
Dynamic Personalization and Smart Blocks
Klaviyo's dynamic blocks let you display different content depending on the recipient's segment, within one and the same email. Example: your cart abandonment email can show a 10% discount code only to new customers, while repeat customers see a reassurance message with no discount.
Klaviyo's AI product recommendations analyze the purchase history of all your customers to automatically suggest the most relevant products to each individual. On Cabania, this block added to our post-purchase emails generated €4,200 in additional monthly revenue with zero manual effort. The algorithm learns continuously and improves over time.
Countdown timers create powerful visual urgency. Be careful not to overuse them, though: if all your emails contain a timer, the effect wears off. Save them for genuine time-limited promotions and for cart abandonment where urgency is justified (limited stock, an offer that really expires).
Copywriting and Systematic A/B Testing
The subject line remains the most critical element of your email: if it does not make people want to open, everything else is useless. Aim for under 50 characters (optimal mobile display), use emojis sparingly (one at most), and personalize with the first name when relevant, but not every time (the effect wears off).
At Superbon, our best-performing subject lines combined a concrete benefit with curiosity: "Marine, your skin is going to love this serum" (38% open rate) versus "New anti-aging serum available" (22% open rate). First name + emotional benefit crushed the basic product description.
The preheader (that short line of text that appears after the subject line) is often neglected, even though it strongly influences the decision to open. Never leave it at the default ("View this email in your browser"); use it to complement the subject line and give an extra reason to open.
In the body of the email, storytelling always beats purely promotional content. Tell why you created the product, share an authentic customer testimonial, explain the problem you solve. In our Cabania emails, the best performance comes from stories of parents describing the impact of the cabin bed on their child's sleep, not from lists of technical features.
A/B testing must be systematic, not occasional. Test one element at a time: subject line one week, CTA the following week, send time the third week. Minimum sample size for a significant test: at least 1,000 recipients per variation, ideally 2,000+. Below that, results are too influenced by statistical chance. Optimizing your conversion rate necessarily requires this culture of constant testing.
Integrations and the Shopify-Klaviyo Ecosystem
Advanced Synchronization with Shopify
The native Shopify-Klaviyo integration automatically syncs tags and segments, but few brands take full advantage of this connection. The Shopify tags you create (VIP, Wholesale, Influencer, Press) appear instantly in Klaviyo and can trigger specific flows or campaign exclusions.
The tags that feed your Klaviyo segments can be applied automatically on the Shopify side. Our guide to automatic customer tagging details the workflows to set up upstream.
Custom properties are even more powerful: create properties in Shopify (number of orders, lifetime value, favorite category) and use them in Klaviyo to build ultra-precise segments. On Cabania, we have a "configuration_type" property that lets us send cross-sell emails perfectly tailored to each type of bed ordered.
Shopify metafields can also be synced to Klaviyo if you configure the integration correctly. This is especially useful for brands with complex catalogs or specific product attributes. Shopify Plus features such as Shopify Flow even let you automate certain actions between Shopify and Klaviyo without going through Zapier.
Powerful Third-Party Integrations
Review apps (Yotpo, Judge.me, Loox) integrate natively with Klaviyo to automatically inject customer reviews into your emails. The result: your cart abandonment emails display the ratings and comments specific to the products involved, creating ultra-relevant social proof that boosts conversion by 15 to 25% according to our tests.
Loyalty programs (Smile.io, LoyaltyLion, Yotpo Loyalty) sync each customer's points balance to Klaviyo, so you can dynamically display "You have 250 points = €12.50 to spend" in every email. This constant visibility of accumulated value is a strong driver of repeat purchases.
Subscription apps (ReCharge, Appstle, Skio) let you segment your subscribers in Klaviyo and send them specific emails (reminder before billing, suggesting a subscription pause rather than a cancellation, upsell to a higher tier). On the subscription brands we support, these flows increase retention by 8 to 12 percentage points.
Product recommendation quizzes (Octane AI, Jebbit) capture valuable "zero-party data" (data the customer gives voluntarily) and push it into Klaviyo. You now know that Marine has sensitive combination skin, is looking for vegan products and has an average budget of €30 per product. This wealth of information enables personalization that goes well beyond simple purchase data.
Klaviyo rarely works alone. Its full potential comes out when it is combined with a coherent app stack: customer reviews to feed your emails, AI chat to capture pre-sale questions, tracking to measure attribution. Our selection of the complete Shopify app stack we recommend lists the 9 other apps we always deploy alongside Klaviyo on our projects.
Webhooks and Custom Development
For brands with very specific needs, Klaviyo webhooks and the API make it possible to build custom integrations. At Stellar Projects, we have developed several custom connectors for our clients: syncing with an external ERP, connecting to a B2B CRM, integrating with a physical point-of-sale system.
Advanced use cases often require specific development: for example, sending an automatic Klaviyo email when a sales rep qualifies a lead in the CRM, or triggering a notification when a key account customer places an order on the site. These cross-system automations create a seamless experience and drastically reduce manual work.
Analytics and Optimization: Measuring ROI
Essential Metrics and Benchmarks
The average e-commerce open rate is around 35-45% in 2025. Below 30%, you probably have a deliverability problem or unengaging subject lines. Above 50%, congratulations, you are in the top 10% of e-commerce brands on Klaviyo. Our average on Cabania: 42%, with peaks at 65% on certain flows such as Back in Stock.
The click rate is generally between 2 and 5%. What really matters is the CTOR (Click-To-Open Rate): of those who opened, how many clicked? A good CTOR exceeds 12-15%. If your CTOR is low despite good open rates, your problem lies in the email content, not the subject line.
The email conversion rate (orders / emails sent) varies enormously by campaign type and sector, but a reasonable benchmark is between 0.5% and 2%. Flows perform better than campaigns: at Superbon, our cart abandonment emails converted at 3.8% while our product newsletters hovered around 1.2%.
Revenue per recipient (revenue generated / number of recipients) is perhaps the most actionable metric. If your RPR drops, either your audiences are fatigued (you are sending too much), your merchandising is weak (unattractive products), or your offers lack punch. Track this KPI monthly and dig in as soon as it slips.
Attribution and Data Reconciliation
Email attribution is a complex subject that sparks heated debate. By default, Klaviyo uses "5-day last-click" attribution: if a customer clicks an email and then buys within 5 days, Klaviyo takes credit for the sale. Google Analytics uses a different attribution model. The result: sometimes significant gaps between the two tools.
Our approach at Stellar Projects: assume the truth lies somewhere between the two figures. Klaviyo slightly overestimates (it takes credit for sales that would have happened anyway), GA4 underestimates (it does not always see the email click in attribution). If Klaviyo says 35% of your revenue and GA4 says 22%, reality is probably around 28-30%.
Multi-touch attribution is fairer but more complex. It spreads credit for the sale across every touchpoint in the customer journey: they discovered your brand via Meta, clicked on a product email 3 days later, then searched for your brand on Google before converting. Who deserves the credit? All three touchpoints played a role. Klaviyo offers linear or position-based attribution models (first touch, last touch) to explore in its advanced analytics.
Continuous Optimization and Audits
A quarterly audit of your flows is essential. Too many brands set up their automations once and then forget about them for months. Yet performance evolves, customer behavior changes, and what worked in January may be suboptimal by June.
During the audit, check: the open and click rates of each email in the flow (the 3rd email of a series often performs very poorly and should be removed), the overall conversion rate, and the revenue generated each month. Compare against your previous benchmarks and Klaviyo's industry standards. If a flow underperforms, test new subject lines, a new timing or different content.
A sunset policy means regularly excluding inactive contacts who never open your emails. It is counterintuitive (deliberately shrinking your list?), but essential for maintaining good deliverability. Mailbox providers (Gmail, Outlook) monitor engagement with your emails, and if 40% of your recipients never open anything, your reputation suffers and you end up in spam. At Stellar Projects, we recommend excluding contacts with no opens at all in 180 days, after one last win-back attempt.
Your testing roadmap should be planned quarterly: in January you test subject lines, in February CTAs, in March send times, in April email design, and so on. This systematic approach guarantees continuous improvement in your email performance.
Klaviyo Costs and ROI
Pricing and Price Structure
Klaviyo offers a free plan for up to 250 contacts and 500 email sends per month, which lets you try the tool risk-free when you are starting out. Beyond that, pricing is based on the number of active contacts (those who have opened or clicked an email in the last 6 months).
A concrete pricing example: for 1,000 active contacts, expect about €45/month. For 5,000 contacts: €150/month. For 10,000 contacts: €275/month. Note that inactive contacts (who never engage) are not billed, hence the importance of the sunset policy mentioned above.
SMS is billed on top: about €0.015 per SMS in France, or €15 for 1,000 SMS sent. On our brands, we use SMS sparingly (VIP cart abandonment, flash alerts, shipping notifications only) because the channel is more intrusive and wears out quickly if overused.
Expected ROI and Payback
For a properly optimized e-commerce store, email marketing generates on average 25 to 35% of total revenue. That is huge, and it is why investing in Klaviyo is a no-brainer. At Stellar Projects, we have clients for whom email accounts for up to 42% of revenue (a record held by a beauty brand with a highly engaged list).
Payback time is generally 1 to 3 months. In practical terms: you invest €150/month in Klaviyo + about €1,000 for a well-executed initial setup (templates, flows, segmentation). From the second month, email generates enough revenue to cover the investment, and after that it is pure profit.
A worked example for a store doing €50k in monthly revenue: with optimized email marketing accounting for 30% of revenue, you generate €15k through Klaviyo. Total cost: €150/month for the subscription + say 10 hours of in-house management per month (campaigns, monitoring), or about €400 in fully loaded salary cost. A total of €550 to generate €15k. ROI: 27:1. It is simple math.
Total Cost of Ownership
Beyond the Klaviyo subscription, factor into your budget: the initial setup (between €1,500 and €5,000 depending on whether you do it in-house, with an agency or through a freelancer), the design of custom branded templates if you do not want to use Klaviyo's (budget €800-2,000 for a complete kit), and monthly management time, which ranges from 5 hours (the bare minimum, just monitoring) to 20+ hours (weekly campaign creation, testing, optimization).
At Stellar Projects, our Klaviyo support services start at €2,500 for a complete setup including 10 essential flows, branded templates, advanced segmentation and training for your team. For brands that prefer to delegate entirely, our managed service plans run around €1,500/month (regular campaigns + monitoring + continuous optimization).
Deliverability, GDPR and SMS: The Foundations to Secure
Before trying to optimize a single click rate, make sure your emails actually land in the inbox and that your data collection is legally watertight. These foundations are invisible when everything is going well, and catastrophic when neglected: it is the first thing we check in every Klaviyo account audit.
Domain Authentication: SPF, DKIM, DMARC
Set up a dedicated sending domain and authenticate it with all three protocols: SPF, DKIM and DMARC. Since Gmail and Yahoo tightened their requirements, an unauthenticated domain is almost always filtered into spam, whatever the quality of your content. The setup is done once, in the Klaviyo settings and your DNS zone, and everything else in your email program depends on it.
If you are starting out or changing your sending domain, go through a warm-up phase: gradually ramp up volumes on your most engaged segments for 2 to 4 weeks before expanding to your whole list. And clean up hard and soft bounces continuously: Klaviyo removes some of them automatically, but a monthly review prevents the drift that damages your sender reputation.
GDPR and Consent
Three requirements to lock down for a French or European brand: double opt-in (our standard recommendation, see the setup section), a clear preference management link in every email, and keeping proof of consent (source, date and original form), which Klaviyo records natively on each profile. Also remember to document Klaviyo in your record of processing activities and your privacy policy, as with any tool that processes personal data.
SMS: Powerful, as Long as It Stays Complementary
SMS boasts record read rates, but it is an intrusive channel that wears out quickly. Our rule on our own brands and for our clients: a separate opt-in from email, strictly complementary scenarios (VIP cart abandonment, restock alerts, delivery tracking), and a strict cadence to avoid marketing fatigue. Combined with the sunset policy described in the analytics section, these practices protect your sender reputation and deliverability over time.
Common Mistakes to Avoid
Over-mailing is the #1 mistake we see. Some brands send 5 emails a week to their entire list, then wonder why their open rates are dropping and their unsubscribes are skyrocketing. Email fatigue is real: beyond 3-4 emails a week, you enter the danger zone. On Cabania, we send a maximum of 2 emails a week (excluding automated flows), and our unsubscribe rate stays below 0.15%.
Poor segmentation, or worse, no segmentation at all, kills performance. Sending the same email to your whole list ("spray and pray") converts 2 to 3 times less than an email segmented by behavior or profile. If you do only one thing after reading this article, start segmenting: new vs. repeat customers at a minimum, ideally by product category and engagement level.
Neglecting mobile optimization is inexcusable in 2025. Test ALL your emails on iPhone and Android before sending. A template that looks good on desktop but breaks on mobile means 70% of your recipients see an unreadable mess and delete it immediately.
Ignoring A/B testing is a costly mistake. Every successful test improves your performance by 5, 10, sometimes 30%. Over a year, the cumulative effect is massive. Yet many brands keep sending the same emails with the same subject lines without ever testing variants. That is leaving money on the table.
Poor send timing can sink your performance. There is no universal best time; it depends on your audience. Test: for Superbon (women aged 30-50), the sweet spot was Tuesday and Thursday at 11am. For Cabania (parents of young children), Sunday at 8:30pm worked surprisingly well (a quiet moment after the kids are in bed). Your customers have their own rhythms, so find out what they are.
Underusing Shopify data is a waste. Klaviyo gives you access to a behavioral goldmine, so use it! Products viewed, categories explored, average order value, purchase frequency: it is all there. Yet we still see brands sending generic emails without any dynamic personalization.
Not cleaning your lists regularly gradually erodes deliverability. Inactive contacts who never open your emails signal to mailbox providers (Gmail, Outlook) that your content is not relevant. The result: you start landing in spam, even for your engaged contacts. Set up a sunset policy and accept shrinking your list to improve its quality.
Our Klaviyo Support at Stellar Projects
Everything this guide describes, our Klaviyo agency for Shopify puts in place for you, from the initial setup to monthly management. And to explore each topic in depth, our ultimate Klaviyo guide brings all of our tutorials together.
Audit and Tailored Strategy
At Stellar Projects, we always start with a complete audit of your current setup, whether you are already on Klaviyo or on another tool. This audit analyzes: your existing flows and their performance, your segmentation (or lack of it), your email design and conversion rates, your deliverability, and your immediate quick wins.
We also always benchmark your competitors: which emails they send, how often, with which offers and in what tone. Not to copy them, but to identify opportunities to differentiate and industry best practices to adapt. In the ultra-competitive cosmetics market, this competitive analysis showed us that 80% of brands were neglecting post-purchase, creating a massive opportunity for Superbon.
The tailored roadmap that follows prioritizes actions by impact/effort: quick wins first (often fixing a misconfigured flow or improving a subject line), then medium-term workstreams (advanced segmentation, new flows), and finally long-term projects (custom integrations, complex automation).
Complete Setup and Migration
Our complete setup service includes: the technical Klaviyo-Shopify configuration with all advanced syncs, the creation of the 10 essential flows (welcome, cart abandonment, post-purchase, browse abandonment, back in stock, win-back, VIP, etc.), the design of branded, mobile-optimized email templates, and basic segmentation setup (RFM at a minimum, behavioral by category).
If you are migrating from Mailchimp, Omnisend or another tool, we handle the entire process: exporting your list while preserving its history (to the extent technically recoverable), recreating your segments and flows in Klaviyo, a gradual migration with a dual-sending period to secure the transition, and above all zero downtime. Your customers should not even notice the change.
Training for your team is always included: a 2-3 hour session by video call or in person where we train your marketing teams on day-to-day use of Klaviyo, campaign creation, performance analysis and best practices. We also provide custom documentation tailored to your specific setup, not a generic guide.
Support for 30 days after launch ensures you are never stuck: technical questions, flow optimizations, strategic advice, we remain available throughout the critical launch phase.
Managed Service for Hyper-Growth Brands
For brands that prefer to focus on their core business (product, acquisition, operations), we offer fully managed Klaviyo services: creating and sending monthly campaigns (product newsletters, promotions, launches), continuous flow optimization (A/B testing, adjustments based on performance), weekly KPI monitoring with alerts in case of anomalies, and detailed monthly reporting with recommendations.
This model works particularly well for brands doing €200k+ in monthly revenue: at that stage, email generates €50-80k in monthly revenue, and having a dedicated specialist optimizing continuously makes a measurable difference of several thousand euros per month. The cost of a managed service (€1,500-2,500/month depending on complexity) is more than offset by the additional performance it generates.
Why Work with a Shopify Agency on Klaviyo?
It is a fair question: why hire a specialized Shopify agency rather than managing Klaviyo in-house or through a generalist email marketing freelancer?
Our added value at Stellar Projects rests on three pillars. First, we are e-commerce practitioners ourselves (Superbon, Cabania), not just consultants. We know the operational reality, inventory constraints, margin issues, and the trade-offs between acquisition and retention. This hands-on experience informs our strategic recommendations.
Our Shopify technical expertise makes all the difference on advanced integrations. A typical email marketing consultant does not necessarily know how to use Shopify metafields in Klaviyo, how to properly set up product tracking on a custom theme, or how to integrate Klaviyo with your ERP via API. We do, because it is what we do every day.
Finally, our holistic approach connects email to the rest of your marketing stack: CRO, SEO, paid acquisition. Email does not live in a silo; it is part of an overall strategy. When we optimize your Klaviyo flows, we also look at your Shopify conversion funnel, your landing pages and your merchandising. Our tailored Klaviyo support is part of this 360° vision.
Still unsure about how to choose the right partner for your Klaviyo project? We offer a free 30-minute audit where we analyze your current setup, identify your quick wins and give you recommendations you can act on immediately, whether you work with us or not. Zero fluff, 100% value.
Whether you are starting from scratch or looking to optimize an existing setup that is underperforming, we have probably already handled a similar case and know exactly how to unlock your email growth. Our Klaviyo agency handles the setup, the flows and the management of your retention. And to explore the tool in depth, our ultimate Klaviyo guide brings all of our tutorials together.
Contact us to discuss your project!
