Most ecommerce stores treat their email list as a single audience. They draft a campaign, send it to everyone, and hope for the best. This approach is leaving substantial revenue on the table and, worse, actively damaging deliverability by sending irrelevant content to disengaged subscribers.
Properly segmented ecommerce email campaigns generate 3-5 times more revenue per recipient than unsegmented broadcasts. That is not a marginal improvement. It is the difference between email being a cost centre and email being your most profitable marketing channel.
Over twenty years of operating and advising ecommerce brands, we have refined a segmentation framework that balances sophistication with practicality. This guide walks through exactly how to build it, starting with the foundational segments that every store needs and progressing to advanced behavioural targeting that separates good email programmes from exceptional ones.
Why segmentation matters
Segmentation is not about sending fewer emails. It is about sending the right email to the right person at the right time. The benefits compound across three dimensions.
Revenue impact
When you send a new product launch email to your entire list, you get a blended response. Perhaps 25% open it and 2% click. When you send that same email only to engaged subscribers who have previously purchased from the relevant product category, open rates climb to 40-50% and click rates double or triple. The revenue per send is dramatically higher because you are reaching people with demonstrated interest.
Deliverability impact
Email service providers (Gmail, Outlook, Yahoo) evaluate your sender reputation based on engagement metrics. When you send to unengaged subscribers who do not open your emails, your sender reputation deteriorates. Eventually, more of your emails end up in spam or the promotions tab, even for subscribers who want to hear from you.
By segmenting and primarily sending to engaged subscribers, you maintain a strong sender reputation, which improves inbox placement for every email you send.
Customer experience impact
A customer who bought baby clothes three months ago does not want emails about kitchen appliances. A VIP customer who has spent £3,000 this year should not receive the same generic promotional email as someone who signed up yesterday and has never purchased. Segmentation allows you to respect your customers' time by sending content that is genuinely relevant to them.
The best email marketing does not feel like marketing. It feels like a helpful friend who remembers what you are interested in. That is what good segmentation achieves.
Lists vs segments in Klaviyo
Before building segments, you need to understand the distinction between lists and segments in Klaviyo, because they work fundamentally differently.
Lists are static groups. Profiles are added to a list through a specific action — submitting a form, being imported from a CSV, or being added via an API integration. Once on a list, a profile stays there unless manually removed. Lists are useful for tracking acquisition sources (e.g., "Website popup subscribers" or "Trade show leads").
Segments are dynamic groups defined by conditions. Klaviyo evaluates every profile against the segment's conditions in real time. If a profile meets the criteria, they are in the segment. If their behaviour changes and they no longer meet the criteria, they automatically exit. This is what makes segments powerful for ecommerce — they always reflect current customer behaviour.
| Feature | Lists | Segments |
|---|---|---|
| Membership | Static (manually managed) | Dynamic (auto-updates) |
| Best for | Tracking acquisition sources | Targeting campaigns and flows |
| Example | "Email popup subscribers" | "Engaged subscribers who bought in last 90 days" |
| Maintenance | Low | None (automatic) |
| Use in campaigns | Can send to, but less targeted | Ideal for targeted campaign sends |
For campaign targeting, you should almost always use segments rather than lists. Lists tell you where someone came from. Segments tell you who they are now.
The five essential segments
Every ecommerce store should have these five segments built before sending any campaigns. They form the foundation of your segmentation strategy.
1. Engaged subscribers
This is your primary sending audience for regular campaigns. The definition we recommend:
- Has opened or clicked an email in the last 90 days, OR
- Has placed an order in the last 90 days, OR
- Was added to the list in the last 30 days (new subscribers get a grace period)
This segment ensures you are only sending campaigns to people who are actively engaging with your brand. It protects your deliverability while maximising your addressable audience.
2. New subscribers (last 30 days)
People who joined your list in the last 30 days. These profiles are in the early stages of their relationship with your brand. They should receive your welcome series (a core Klaviyo flow) and be treated differently in campaigns — they need more brand education and less hard selling.
3. First-time buyers
Customers who have placed exactly one order. This is a critical segment because the second purchase is the hardest to secure. The repeat purchase rate from first-time to second-time buyer is typically only 25-35% in ecommerce. Targeted follow-up campaigns for this segment — product recommendations, care guides, loyalty incentives — can meaningfully improve retention.
4. Repeat customers
Customers who have placed two or more orders. These are your most valuable profiles. They have demonstrated loyalty and are far more likely to purchase again. This segment should receive early access to new products, exclusive offers, and VIP-tier communications.
5. Lapsed customers
Customers who have purchased before but not in the last 120-180 days (adjust based on your typical repurchase cycle). This segment feeds into your win-back flow and should receive re-engagement campaigns. Understanding why customers lapse — and building communications that address those reasons — is covered in our managed Klaviyo services offering.
Behavioural segments
Once the foundational segments are in place, behavioural segmentation is where the real revenue gains emerge. These segments use Shopify data synced to Klaviyo to target customers based on what they have done, not just who they are.
Product category buyers
Create segments for each of your major product categories. If you sell skincare, you might have segments for "Moisturiser buyers," "Serum buyers," and "Cleanser buyers." This allows you to:
- Send new product launches to customers who buy from that category
- Cross-sell complementary products to customers in adjacent categories
- Identify replenishment timing for consumable products
Average order value tiers
Segment customers by their average order value to tailor pricing and promotion strategy:
- Budget shoppers (AOV below £30): Respond well to free shipping thresholds and bundle deals
- Mid-range shoppers (AOV £30-£80): Respond to curated collections and new arrivals
- High-value shoppers (AOV above £80): Respond to exclusivity, early access, and premium positioning
Purchase frequency
How often a customer buys tells you how to communicate with them. Monthly buyers can receive weekly emails without fatigue. Quarterly buyers should receive fewer, more impactful sends. Annual buyers (gift purchasers) should receive pre-seasonal reminders.
Browse behaviour
Klaviyo tracks which products and collections visitors view on your Shopify store. Use this data to build segments of people who have viewed specific categories but not purchased. These "high-intent non-buyers" are excellent targets for category-specific promotions and content.
RFM segmentation for ecommerce
RFM (Recency, Frequency, Monetary) analysis is the gold standard for ecommerce customer segmentation. It scores customers across three dimensions to identify your most and least valuable segments.
| Dimension | What it measures | Why it matters |
|---|---|---|
| Recency | How recently a customer purchased | Recent buyers are more likely to buy again |
| Frequency | How often a customer purchases | Frequent buyers have higher lifetime value |
| Monetary | How much a customer has spent | High-spend customers justify more attention |
Klaviyo includes predictive analytics that calculate expected customer lifetime value, churn risk, and next expected order date. These predictions layer on top of RFM segmentation to create highly targeted segments:
- Champions: High recency, high frequency, high monetary. Your best customers. Reward them, ask for referrals, offer early access.
- Loyal customers: High frequency but lower monetary. Encourage higher-value purchases through upselling and premium product recommendations.
- Potential loyalists: Recent buyers with moderate frequency. Nurture them towards becoming repeat customers with post-purchase sequences and loyalty incentives.
- At-risk customers: Previously high-value but declining recency. Trigger win-back campaigns before they lapse entirely.
- Lost customers: Low recency, regardless of previous frequency or monetary value. Attempt re-engagement, but accept that some customers will not return.
The power of RFM is that it treats different customer groups differently. A "Champions" campaign should feel exclusive and appreciative. An "At-risk" campaign should feel urgent and offer a compelling reason to return. Sending the same message to both groups wastes the opportunity.
Engagement-based segments
Engagement segmentation is essential for deliverability management and should be layered on top of purchase-based segmentation.
Engagement tiers
- Highly engaged: Opened or clicked in the last 30 days. Send everything — campaigns, new products, content.
- Engaged: Opened or clicked in the last 30-90 days. Send regular campaigns but perhaps not every email.
- Semi-engaged: Opened or clicked in the last 90-180 days. Send only your best campaigns — sales, major launches, high-value content.
- Unengaged: No opens or clicks in 180+ days. Do not send regular campaigns. Move into a sunset/re-engagement flow.
The sunset flow
Profiles that have not engaged in 180 days enter a sunset flow — a final sequence of 2-3 emails asking if they still want to hear from you. If they do not re-engage, suppress them. This is not losing subscribers; it is cleaning your list of people who were already ignoring you.
Maintaining a clean, engaged list is one of the most impactful things you can do for your email programme's long-term health. As we discuss in our overview of Klaviyo management costs, list hygiene is a core component of professional email management.
Using segments for campaign targeting
Building segments is only half the equation. Using them strategically in your campaign planning is what drives results. Here is how to think about targeting for different campaign types.
Product launch emails
Send to engaged subscribers who have previously purchased or browsed the relevant product category. Optionally, send to your broader engaged segment 24-48 hours later as a wider launch.
Sale and promotion emails
Send to your full engaged segment. These are your highest-reach campaigns. Consider excluding recent purchasers who bought at full price within the last 7 days to avoid buyer's remorse.
Content and educational emails
Send to your engaged segment. Content emails are valuable for maintaining engagement during periods between product launches. They also help warm up new subscribers before asking for a purchase.
Re-engagement campaigns
Target your semi-engaged and unengaged segments specifically. Use compelling subject lines and clear value propositions. "We miss you" emails rarely work. "Here is what you have missed" with genuine product updates performs better.
VIP and loyalty communications
Target repeat customers and high-value segments only. Early access, exclusive previews, loyalty rewards. The exclusivity must be real — if "VIP" customers later see the same offer sent to everyone, trust is broken.
Your abandoned cart sequences should also leverage segmentation, treating high-value cart abandoners differently from low-value ones.
List hygiene and suppression
Segmentation without list hygiene is incomplete. Your email list naturally degrades over time as people change email addresses, lose interest, or switch to competitors. Proactive list management keeps your metrics accurate and your deliverability strong.
Regular suppression
- Hard bounces: Suppress immediately. These are invalid addresses and sending to them damages your sender reputation directly.
- Soft bounces: Suppress after 3-5 consecutive soft bounces. The address may be temporarily unavailable.
- Unsubscribed profiles: Klaviyo handles this automatically, but verify that your suppression lists are properly configured.
- Spam complaints: Suppress immediately and permanently. Even one complaint per 1,000 sends is concerning to email providers.
Sunset schedule
Run a sunset flow quarterly. The sequence should be:
- Email 1: "We have not heard from you in a while. Here is what is new." Include your best recent product or content.
- Email 2 (3 days later): "Do you still want to hear from us? Click here to stay subscribed." Include a clear re-subscription link.
- Email 3 (5 days later): "Final email. We are removing you from our list to keep things tidy. Click here if you want to stay." Final chance before suppression.
Profiles that do not engage with any of these three emails should be suppressed. You can always re-add them later if they return to your site and take a meaningful action.
Common segmentation mistakes
We see the same errors repeatedly when auditing ecommerce email programmes. Avoid these.
Over-segmenting
Creating 50 micro-segments sounds sophisticated but creates a management nightmare. If a segment has fewer than 500 profiles, it is too small for most campaign purposes. You cannot draw meaningful performance conclusions from campaigns sent to tiny groups. Start with 8-12 segments and add more only when you have the volume and the content strategy to support them.
Ignoring engagement in favour of demographics
Demographics (age, gender, location) are less predictive of purchase behaviour than engagement data and purchase history. A 25-year-old who has not opened an email in six months is a worse campaign target than a 55-year-old who opened and clicked last week. Prioritise behavioural segments over demographic ones.
Setting and forgetting
Segments need periodic review. The conditions that defined your "VIP customer" segment when you had 500 customers may not be appropriate when you have 5,000. Review your segment definitions quarterly and adjust thresholds as your customer base grows.
Not suppressing unengaged profiles
This is the most common and most damaging mistake. Sending to unengaged profiles does not just waste money on Klaviyo billing — it actively harms your deliverability for engaged subscribers. The short-term impulse to "maximise reach" causes long-term damage to inbox placement.
Treating all new subscribers the same
A subscriber who signed up through a 10% discount popup has different intent from someone who subscribed through a blog content upgrade. If possible, segment new subscribers by acquisition source and tailor your welcome series accordingly.
How to implement this
If you are starting from scratch or have an unsegmented list, here is the order of implementation we recommend.
Week 1: Build foundational segments
Create the five essential segments in Klaviyo: engaged subscribers, new subscribers, first-time buyers, repeat customers, and lapsed customers. Start sending campaigns only to your engaged segment.
Week 2-3: Add engagement tiers
Build highly engaged, engaged, semi-engaged, and unengaged segments. Set up a sunset flow for unengaged profiles. Begin suppressing profiles that fail the sunset sequence.
Week 4-6: Layer behavioural segments
Create product category segments, AOV tiers, and purchase frequency segments. Begin using these for campaign targeting alongside your engagement segments.
Month 2-3: Implement RFM
Build RFM-based segments using Klaviyo's predictive analytics. Create differentiated campaign strategies for Champions, At-risk, and other key RFM groups.
Ongoing: Test, measure, refine
Review segment performance monthly. Look at open rates, click rates, revenue per recipient, and unsubscribe rates by segment. Adjust segment definitions and campaign targeting based on what the data tells you.
If this feels overwhelming, it does not have to be done alone. Our Klaviyo email marketing service includes full segmentation setup, ongoing list management, and campaign strategy. Start a conversation about where your email programme stands today.
Email segmentation is not a nice-to-have. It is the single most impactful improvement most ecommerce stores can make to their email marketing. Done properly, it increases revenue per send, improves deliverability, reduces unsubscribe rates, and creates a better experience for your customers. Start with the five essential segments, build from there, and let the data guide your evolution.
