Email and SMS are the most profitable marketing channels most ecommerce brands own, and they’re almost always underfunded relative to their contribution.
Omnisend’s 2025 Ecommerce Marketing Report, analysing 24 billion emails sent by ecommerce merchants in 2024, found that automated emails drove 37% of all email-generated sales while accounting for just 2% of total email volume.
One in three people who clicked an automated message made a purchase, compared to one in 18 for scheduled campaign emails. These aren’t marginal gains; they represent a fundamentally different return profile from paid media, where costs rise with scale and platform changes can crater performance overnight.
The strategic argument for email isn’t just about ROI ratios. It’s about ownership. Email and SMS are first-party channels. You own the list, you control the timing, and you’re not subject to algorithm changes, rising CPMs, or platform policy shifts. For ecommerce brands spending heavily on Meta and Google, email is the channel that protects your economics when paid media gets more expensive, and the channel that compounds the value of every customer you acquire.
Email as a Profit Centre, Not a Cost Centre
The fundamental mistake most ecommerce brands make with email is treating it as a communication tool rather than a revenue channel. They send a weekly newsletter, maybe run a sale announcement, and consider that job done. The result is that email typically contributes 15 to 20% of total revenue for average ecommerce brands, when well-run programmes consistently deliver 30% or more.
The difference between those two figures is almost entirely explained by automation. Campaign emails (newsletters, promotions, announcements) require ongoing effort and deliver decent but unremarkable returns. Automated flows (welcome series, abandoned cart, post-purchase, browse abandonment, win-back, replenishment) run continuously, trigger based on customer behaviour, and convert at dramatically higher rates because they reach people at exactly the right moment with exactly the right message.
Most brands have a welcome series and an abandoned cart email. That’s a start, but it’s like having a paid media strategy that consists of one prospecting campaign and one remarketing campaign. The revenue opportunity sits in the depth and sophistication of your automation architecture: how many flows you’re running, how well they’re segmented, how the messaging evolves based on customer behaviour, and how they integrate with your broader marketing strategy.
The Flows That Actually Drive Revenue
Not all automations are created equal, and understanding which flows drive the most revenue helps you prioritise where to invest. The three highest-performing automated email types, according to Omnisend’s data, are abandoned cart, welcome series, and browse abandonment, which together accounted for 87% of all automated orders in 2024. But there are several additional flows that separate basic email programmes from genuinely profitable ones.
Post-purchase sequences are where retention economics begin. The first email after a purchase isn’t a receipt; it’s the beginning of the relationship. A well-structured post-purchase flow includes order confirmation, shipping updates, a delivery follow-up requesting a review, an educational email about the product (care instructions, usage tips, complementary products), and a timed cross-sell or replenishment prompt. Each of these emails serves a dual purpose: improving the customer experience and creating the conditions for a second purchase.
Win-back flows target customers who haven’t purchased within a defined period, typically based on your brand’s average time between orders. If your data shows that 70% of repeat purchases happen within 90 days, a win-back sequence beginning at day 75 catches customers before they lapse. The messaging should escalate in urgency and incentive: a reminder, then a product recommendation, then a modest offer, then a final “we miss you” with a stronger incentive. Brands that don’t have win-back flows are effectively letting churned customers disappear without any attempt at recovery.
Replenishment flows work for any consumable or recurring-need product. If you sell coffee, supplements, skincare, or pet food, you know roughly how long each product lasts. A timed replenishment email that arrives a few days before the customer is likely to run out converts at rates that dwarf standard promotional campaigns, because the timing matches a genuine need.
Metrics That Reveal Whether Your Programme Is Working
Most brands measure email by open rate and click rate, both of which are increasingly unreliable indicators of actual performance. Open rates have been inflated since Apple’s Mail Privacy Protection launched in 2021, which pre-loads email content and registers opens that never actually happened. Click rates are more useful but still don’t tell you whether the programme is generating revenue.
The metrics that matter for ecommerce email are revenue per recipient (RPR), flow revenue versus campaign revenue split, list growth rate, and deliverability. Revenue per recipient tells you how much revenue each email generates on average across your subscriber base. It’s the single best indicator of programme health because it captures both engagement and conversion in one number. If your RPR is declining, something is wrong, whether it’s list fatigue, poor segmentation, or deliverability issues.
The flow versus campaign revenue split reveals how much of your email revenue comes from automated flows versus manually sent campaigns. For a mature ecommerce email programme, flows should generate at least 40% of total email revenue, and often more. If campaigns account for 80% or more of your email revenue, your automation architecture is underbuilt, and you’re leaving money on the table every day those flows aren’t running.
List growth rate matters because your email list is a depreciating asset. Subscribers disengage, email addresses become invalid, and people unsubscribe. If you’re not consistently growing your list at a rate that outpaces natural attrition, your addressable audience is shrinking. List growth should be measured net of unsubscribes and bounces, not just raw new subscribers.
Deliverability is the metric that underpins everything else. If your emails aren’t reaching inboxes, nothing else matters. Deliverability issues are often invisible because most email platforms report “delivered” as reaching the server, not the inbox. Monitoring inbox placement rates, spam complaint rates, and engagement-based reputation scores (particularly with Gmail and Microsoft) should be a regular discipline, not something you investigate only when revenue drops.
How Email Strategy Should Integrate with Paid Media
Email and paid media aren’t separate channels; they’re parts of the same acquisition and retention system. The integration points between them are where the most value is created, and where most brands have gaps.
The most direct connection is between paid media acquisition and email capture. Every visitor your paid campaigns bring to the site who doesn’t purchase but does subscribe to your list becomes a future conversion opportunity at a fraction of the original acquisition cost. Your on-site email capture strategy (pop-ups, embedded forms, exit-intent offers) directly affects the efficiency of your paid media spend. A site that captures 5% of visitors as email subscribers versus one that captures 2% gets dramatically more long-term value from the same media budget.
The second integration point is audience suppression and segmentation. Customers already in active email flows (particularly those in a post-purchase sequence or approaching a replenishment window) often don’t need to be targeted with paid remarketing. Suppressing these audiences from paid campaigns reduces wasted spend and avoids the irritation of being hit with ads for a brand you’re already buying from. Conversely, email non-openers and lapsed subscribers may be better reached through paid remarketing than through more emails they’re not reading.
The third connection is data feedback. Email engagement data (who opens, who clicks, who purchases, who ignores) provides valuable signal about customer preferences and purchase intent that should inform paid media targeting and creative strategy. An ecommerce marketing partner that manages both email and paid media can use this data to create a more efficient overall system. When these functions sit in separate agencies with no shared data, both channels perform worse than they should.
When to Bring in a Specialist
Most ecommerce brands start email in-house, and for brands under £2M in revenue, that’s often the right call. A competent marketing generalist with access to a platform like Klaviyo or Omnisend can set up basic flows and run campaigns effectively. The value of a specialist email agency or consultant increases at certain thresholds.
The first is when your email programme has been running for 12 months or more but revenue contribution has plateaued or declined. This usually signals that the automation architecture needs expanding, the list needs better segmentation, or there are deliverability issues that require specialist diagnosis.
The second is when your business has moved past the basic flows and needs more sophisticated lifecycle marketing: multi-branch welcome series based on acquisition source, dynamic product recommendations, predictive send-time optimisation, or complex segmentation based on purchase history and engagement patterns. These capabilities require both strategic knowledge and technical platform expertise that generalists typically lack.
The third is when email and SMS need to integrate more closely with paid media, CRO, and overall business strategy. At £5M+ in revenue, email should be contributing 25 to 35% of total revenue, and the programme should be actively informing decisions about acquisition strategy, product merchandising, and customer segmentation. That level of integration requires either a specialist agency or a senior in-house resource working closely with your other marketing partners.
Whatever route you choose, the essential requirement is that email is treated as a revenue channel with the same rigour, measurement, and strategic attention as paid media. For brands that want that kind of integrated approach, Rozee Digital builds retention programmes that connect directly to acquisition strategy, so every channel works harder because the others exist.
