Marketers will A/B test a button colour 12 times. They’ll build lightning-fast checkouts and obsess over heatmaps. But ask when they last optimised their email flows? Cue the awkward silence.
That’s a problem.
Because even the slickest on-site experience won’t convert if your emails aren’t pulling their weight. If they’re not getting opened, clicked or converting - you’ve lost your customer before they even see that beautifully optimised product page. To borrow a phrase:
“A website without email marketing is like a billboard in the desert.”
Below, we break down five of the biggest CRO mistakes in email marketing - and how to fix them with real data and results.
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Treating email like a broadcast, not a conversation
Mistake: Sending the same content to everyone, regardless of their behaviour or interests.
Consequence: Irrelevant emails get ignored, marked as spam, or lead to unsubscribes. Over time, this hurts your sender reputation - meaning even your best emails could land in the junk folder. If they don’t land in the inbox, they won’t get opened, clicked, or converted.
Fix: Use segmentation and dynamic content blocks in platforms like Klaviyo to personalise based on browsing behaviour, past purchases, and engagement level. Speak directly to what each customer actually cares about - and your deliverability, engagement, and revenue will all improve.
With cookies on the way out, email is one of the best ways to build a direct relationship using zero-party data - what people tell you about themselves. Segmentation helps you use that insight to deliver messages that actually matter to them.
Example from Sciart: A sexual wellness brand boosted performance by switching from generic campaigns to segmented email flows based on product views and past purchase behaviour. The result? A 47.4% open rate and 20% click-through rate - all thanks to smarter, more targeted messaging.
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Over-designing at the cost of clarity
Mistake: Creating beautiful, image-heavy emails that wow in Figma… but fall flat in real inboxes.
Consequence: Slow load times, broken layouts, or unclear CTAs mean your message gets lost - especially on mobile, where most emails are opened.
Fix: Design with mobile in mind. Use short paragraphs, high contrast, visible CTAs, and fast-loading elements. Try A/B testing designed vs. stripped-back layouts (even plain text) for certain flows like abandoned cart or transactional emails.
Pro tip: View your email on your phone - in dark mode, on 4G. If you can’t tell what to do within two seconds, your customer won’t either.
Want more confidence? Use tools like Litmus, Email on Acid, or Mailtrap to preview across devices, browsers, and clients before sending.
3. Neglecting subject lines and preview text
Mistake: Writing them as an afterthought - or not testing them at all.
Consequence: You could have the best-designed email in the world, but if no one opens it, it’s worthless. Subject lines and preview text are your first impression - if they don’t earn attention, the conversion opportunity vanishes.
Fix: You could use A/B testing to apply Cialdini’s 7 principles of persuasion to your subject lines and hooks:
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Reciprocity: “We’ve saved something just for you”
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Scarcity: “Almost gone - don’t miss out” Just be aware, words and phrases that communicate urgency are often detected by spam filters.
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Authority: “Doctor-recommended - now back in stock”
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Consistency: “Still interested in [product]? We thought so.”
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Liking: “We picked this just for you, based on what you love”
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Social Proof: “Join 2 Million Satisfied Customers”
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Unity: “From our community, to you”
Real data: We A/B tested two subject lines - one offering “Up to 50% OFF”, the other spelling out the dollar savings (“Up to $95 OFF”).
The $95-off version drove a 1.39% lift in open rate - small on paper, but statistically significant with an 82% win probability. For high-volume sends, that kind of gain can mean thousands in extra revenue.
Pro tip: Don’t waste your preview text. Use it to build on your subject line with contrast, curiosity, or a clear benefit.
The subject gets the open; the preview drives the click.
Your subject line isn’t a summary - it’s a hook. If it doesn’t make you want to click, it won’t work on your customers either.
4. Missing the moment of intent
Mistake: Slow or static flows that miss a hot lead.
Fix: Use your email provider’s predictive send time, abandonment triggers, and real-time alerts.
Example: A browse abandonment email sent 24 hours after a toy was viewed generated 357% more revenue than one sent just 4 hours later.
Why? Because timing isn’t always about speed. In this case, giving customers a bit more breathing room - rather than jumping in too quickly - led to higher conversions. Sometimes, a well-timed nudge works better than an instant reminder.
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Relying too much on campaigns, not enough on flows
Mistake: Prioritising one-off campaigns while neglecting automated flows - the real workhorses of conversion.
Fix: Map your customer journey and build out essential lifecycle flows - these are where the real conversion opportunities lie:
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Welcome: Make a strong first impression that drives first clicks and conversions.
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Abandoned cart & browse: Nudge them when interest is high - but don’t go too early.
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Post-purchase: Turn buyers into loyal customers with thoughtful follow-ups.
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Replenishment: Perfect for consumables or products with regular usage cycles.
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Winback: Reignite interest in those who’ve drifted.
Each one isn’t just a flow - it’s a moment to move someone closer to your brand (and their next purchase).
Flows often get overlooked because they aren’t as visible or exciting as a big new campaign. But they quietly do the heavy lifting of conversion - day in, day out.
Stat to know: Klaviyo’s 2024 benchmark data shows brands with strong lifecycle flows drive up to 70% more email-attributed revenue than those without.
Example: A skincare brand saw an 83% increase in repeat purchases by using automation to trigger replenishment emails based on purchase history and predicted reorder windows. Over 56% of total revenue came from email.
Flows aren’t just “set and forget” systems. They’re CRO tools - each one a mini funnel designed to move a user closer to conversion.
Other Quick Wins Worth Testing:
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Predictive product recommendations
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Send time optimisation
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A/B testing subject lines across segments
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Attribution clean-up: are you really tracking what’s working?
Final Thought: Email Isn’t Just a Retention Channel
It’s one of your most powerful conversion tools - if you treat it like one.
Optimising flows, subject lines, and timing might not be as sexy as redesigning your homepage. But the impact is often bigger. And better yet, it compounds over time.
If you care about conversion, you can’t afford to ignore email. These optimisations aren’t just tweaks - they’re leverage points that drive revenue long after the send button’s hit.”
Bonus Offer
Want to know where your emails are leaking conversions?
Sciart is offering a free email flow audit just for EAN readers. We’ll spot the gaps and show you exactly how to fix them.
Reach out now to book yours.
