Klaviyo guide, Stellar Projects
Klaviyo is the email and SMS marketing platform most widely used by e-commerce brands on Shopify. Its strength is not sending emails, which any tool can do, but data: Klaviyo reads each contact's buying behavior and triggers the right message at the right time, automatically.
This page brings together our resources on the subject, from discovering the tool to advanced flows. Each step (understanding, comparing, installing, segmenting, automating) has its own dedicated guide. Below you will find the context to know which one to open depending on where you are.
Email is not an acquisition channel, it is a profitability channel. It works on an audience you have already acquired, which makes it the highest-return lever in e-commerce.
- What Klaviyo actually does
- Klaviyo versus the alternatives
- What Klaviyo really costs
- Installing Klaviyo and connecting it to Shopify
- Segmentation, the heart of the system
- The automated flows to set up
- Migrating from another tool
- Measuring results without getting it wrong
- Training up or getting support
- Going further: resources in this topic cluster
Where to start? If you are new to the tool, first open our introduction to Klaviyo. If you are still hesitating with a competitor, go to the Mailchimp comparison or the Brevo one. If the tool is already installed but isn't producing anything, your problem is almost always segmentation.
1. What Klaviyo actually does
A classic emailing tool sends a message to a list. Klaviyo works differently: it connects to your store, ingests each contact's browsing and purchase history, and makes that data usable for targeting and triggering.
In practice, a contact is no longer an email address but a profile: what they viewed, what they bought, when, for how much, how often. Our page on what Klaviyo is explains this logic in detail, and our rundown of Klaviyo's main features covers the exact scope of the tool.
The four building blocks of the platform:
- Profiles, which aggregate each contact's data from the store
- Segments, which split the audience by behavioral criteria and are recalculated continuously
- Flows, sequences triggered by an action: abandoned cart, first purchase, inactivity
- Campaigns, one-off sends to a segment, for a new product or a promotion
This distinction between flows and campaigns is what shapes everything else. Flows work continuously with no intervention, while campaigns require a decision for every send. In a mature setup, flows generate most of the email revenue.
2. Klaviyo versus the alternatives
Klaviyo is not always the right choice, and the comparison depends mainly on what you do with the data. If you send the same monthly newsletter to your entire list, a general-purpose tool will be enough and will cost less.
The gap widens as soon as you want to trigger messages based on buying behavior. Our detailed comparisons cover the two most common head-to-heads on the French market: Mailchimp or Klaviyo, and Brevo or Klaviyo.
The real criterion is not the advertised monthly price, but the attributable revenue the tool allows you to generate. A tool that costs half as much but produces a third of the email revenue is a bad calculation.
3. What Klaviyo really costs
Klaviyo's pricing is based on the number of active profiles in your list, not on the volume of emails sent. This is a fundamental difference: a poorly maintained list, inflated with inactive contacts, costs you money every month without bringing anything in.
Hence a management rule many discover too late: regularly cleaning out inactive profiles doesn't just improve deliverability, it directly reduces the bill. Our page on what Klaviyo costs details the tiers and the line items to plan for.
SMS is billed separately, per send. It is much more expensive than email per message, but its read rate justifies it for specific uses, such as high-value cart reminders or back-in-stock alerts, as long as you don't overuse it.
4. Installing Klaviyo and connecting it to Shopify
The Shopify integration is native and quick, but the default installation is not enough. Three points need explicit configuration, otherwise you will lose data or deliverability.
- Sending domain authentication. Without DNS configuration, your emails go out from a generic domain and end up in promotions or spam.
- On-site behavioral tracking. This is what feeds profiles with the pages and products viewed, and therefore all the targeting that follows.
- Consent collection. Forms, checkboxes and double opt-in, to be set up from the start for regulatory reasons as much as for list quality.
Our step-by-step guide to setting up Klaviyo on Shopify covers all these settings, and our complete guide to the Klaviyo Shopify integration covers the setup as a whole.
5. Segmentation, the heart of the system
This is where most setups fail. Klaviyo installed but used to send the same message to the whole list is no better than a basic tool, while costing more.
A segment is not a fixed list but a permanent query: contacts enter and leave it automatically based on their behavior. Our guide to creating Klaviyo segments details how to build these rules.
The segments that deliver the most results, in our experience:
- Best customers, by frequency and cumulative spend, to be treated differently from everyone else
- At-risk buyers, once active and silent since, to re-engage before they are lost
- Subscribers who have never bought, who have an identifiable barrier: price, trust or missing information
- Buyers of a specific category, for product targeting that makes sense
Start with these four. Overly fine segmentation from the outset produces segments too small to be statistically useful and a lot of work for nothing.
6. The automated flows to set up
Flows are what separate a profitable setup from a tool that sits idle. They run continuously, require no intervention once configured, and generally account for the bulk of the revenue generated by email.
Our guide to creating Klaviyo email sequences details the mechanics. Here is the order of priority we apply:
- Abandoned cart. The most profitable, every time. It works on purchase intent already expressed, which explains conversion rates far beyond those of a standard campaign. Our dedicated article on abandoned cart recovery covers this flow in depth.
- Abandoned browse. Same logic, further upstream: the visitor viewed products without adding to cart. A weaker signal, so a lighter message.
- Welcome. The moment when attention is at its peak. This is where a subscriber's first order is won or lost.
- Post-purchase. Confirmation, usage tips, then an invitation to leave a review. It sets up the repeat purchase and feeds your social proof.
- Reactivation. For contacts who have gone silent, before removing them from the list, and therefore from the bill.
Don't launch all five at once. A well-written abandoned cart flow brings in more than five rushed flows launched on the same day.
7. Migrating from another tool
Switching emailing platforms is often more worrying than it needs to be, provided you handle two issues properly.
The first is data: contacts, consent history, unsubscribe statuses. That last point is non-negotiable: reimporting an unsubscribed contact is a regulatory breach as much as a complaint risk.
The second is deliverability. A domain that suddenly sends a large volume from new infrastructure sets off spam filters. Ramping up gradually, starting with your most engaged contacts, avoids this trap. Our page on migrating to Klaviyo details the steps to follow.
8. Measuring results without getting it wrong
Open rate has become unreliable since the privacy protections that preload images on the mail client side. Relying on it leads to false conclusions.
The metrics that really matter:
- Attributed revenue per flow and per campaign, the only measure that answers the question of return
- Click rate, more reliable than opens because it requires a deliberate action
- Unsubscribe rate, a warning signal about sending pressure or targeting relevance
- Share of revenue generated by email, an indicator of how mature the system is
A word of caution on attribution: Klaviyo naturally claims the revenue it touches, and a customer who would have bought anyway will show up in its stats. Cross-check with your Shopify data before drawing conclusions. Our Shopify CRO guide addresses this question of reliable measurement.
9. Training up or getting support
Klaviyo is accessible without technical skills. Creating a segment, writing a flow or launching a campaign happens in the interface, not in code. The difficulty lies elsewhere: it is strategic and editorial, knowing what to say, to whom and when.
Klaviyo offers its own academy with free certification courses, which is enough for a motivated team to get to grips with the tool. For the Shopify ecosystem more broadly, our article on free and certified Shopify training lists the resources available.
Bringing in an agency makes sense in three cases: a migration where deliverability is at stake, a large list where every conversion point matters a lot, or simply a lack of in-house time to produce content. Our page Stellar, your Klaviyo agency details our approach, and our comparison of the best Klaviyo agencies gives you the criteria to choose, including agencies other than us.
If you would rather talk about it directly, you can contact us about your project.
10. Going further: resources in this topic cluster
This guide is part of a set of resources we maintain on the Shopify and Klaviyo ecosystem. These pages and articles go deeper into the topics covered here.
📚 Stellar Projects guides & resources