9 email marketing mistakes costing e-commerce stores thousands in lost revenue

You know that sinking feeling when you check your Shopify dashboard? Cart abandonment sitting at 73%. Email list with 10,000 subscribers generating maybe $500 a month. You’re not alone.

Here’s what kills me: email marketing delivers a $36-$40 ROI for every dollar spent, making it one of the most profitable channels out there. Yet most store owners treat it like that gym membership they never use.

At Retainful, we’re home to over 20,000 e-commerce stores. My daily job? Checking whether our stores are actually making money from their emails. When new stores start using Retainful, I dig into their setup. And honestly? I see tons of mistakes bleeding their sales and revenue. Same issues. Every. Single. Time.

These aren’t minor tweaks—they’re revenue killers that could easily be fixed in a weekend.

What you’ll learn:

• Why your “personal hate” for emails is costing you thousands
• The popup timing trick that tripled signup rates for stores I’ve audited
• How to rescue emails from spam hell (it’s easier than you think)
• The 5 list segments that’ll double your email revenue

Let’s fix this mess.

Why store owners sabotage their own success

Before anything else, we need to talk about the biggest obstacle to email success: you.

“Nobody opens emails anymore.” “Popups annoy everyone.” “Email is dead.”

When I see store owners on Reddit asking “What are the most common mistakes in email marketing?”, the top answer is always some variation of “not doing it at all because they think it doesn’t work.”

Welcome emails get a 68.6% open rate compared to regular emails at 21.3%. Nearly half of consumers actually WANT weekly promotional emails from brands they like, according to Statista’s consumer research.

The question isn’t whether email works. It’s whether you’re willing to test it properly before killing it.

If you think emails are spammy, create high-quality ones that actually help people. Test basic flows. Look at real data from YOUR store. Then decide.

Mistake #1: Your lead capture form sucks (or doesn’t exist)

No emails captured = no one to sell to. Pretty simple math.

When I audit new stores, probably 60% have that sad little footer form: “Sign up for our newsletter!” Buried at the bottom where absolutely nobody goes. Conversion rate? Maybe 0.3% if you’re lucky.

Some stores DO have great offers but hide them in the footer like it’s a treasure hunt. Others slap an instant popup in my face asking me to “stay updated” with a brand I discovered 2 seconds ago.

Why would I give you my email for that?

When people search “email marketing mistakes examples“, poor lead capture consistently ranks in the top 3 issues across every result.

Fix your lead capture (before you fix anything else)

Timing is everything:

• Desktop: Exit-intent only (when I move to close the tab)
• Mobile: After 8 seconds OR 60% scroll
• Never: Instant popups. Just… don’t.

I tested this with one of our Shopify stores last month. They were using instant popups (conversion rate: 1.2%). Switched to exit-intent on desktop and 8-second delay on mobile. Conversion rate jumped to 3.8%. Same offer. Different timing.

Give real value:

Don’t just ask for emails—trade something worth having. Here’s what actually works based on data from our 20,000+ stores:

Offer Type	Conversion Rate	Works Best For
15-20% discount	3-5%	Most stores
Dollar discount ($15-$25)	3-6%	Orders over $100
Free gift	4-7%	Physical products
Free shipping	2-4%	When you charge shipping
Exclusive guide	3-5%	Educational products

Try this: If your average order is $100 and you offer 20% off, customers save about $20. Test offering “$20 off” instead. Same value, different psychology. Sometimes the dollar amount hits harder.

One store I worked with switched from “15% off” to “$15 off” (their AOV was $95). Conversion rate went from 2.9% to 4.2%. Same cost to them. Better results.

Mistake #2: Weak offers that nobody wants

“Subscribe to our newsletter” isn’t an offer. It’s a request with zero value.

“Get updates” means nothing to someone who just discovered your brand.

I see this constantly. A store will spend thousands on Facebook ads driving traffic, then ask visitors to “join the newsletter” with no incentive. It’s like asking someone to give you money because you asked nicely.

The gift strategy nobody uses

Here’s something I don’t see enough: Gift With Purchase. Often beats discounts AND costs less.

One natural skincare store I audited was offering 20% off (costing them about $18 per order on their $90 AOV). Switched to offering a free bamboo soap dish (cost: $2.50) with first purchase. Conversion rate went from 3.1% to 5.4%. They spent less and got more signups.

Research on promotional psychology backs this up—free items trigger stronger emotional responses than discounts.

Digital products or services? Try:

• Free consultation (15-30 minutes)
• Industry-specific templates or guides
• Exclusive training video
• Free audit or assessment

Always exchange value. Nobody owes you their email.

Mistake #3: Your emails look terrible on mobile

This one’s brutal because it instantly cuts your revenue in half.

46% of emails get opened on mobile. For younger customers, it’s over 60%. If your emails aren’t mobile-friendly, half your subscribers see broken, ugly messages.

Last week, I audited a fashion store doing $50K monthly. Their welcome email had beautiful imagery on the desktop. On mobile? Text overlapping images, buttons you couldn’t tap without zooming, and a 15-second load time. Their welcome series had a 22% open rate on mobile vs. 41% on desktop. We fixed the mobile optimization. Mobile opens jumped to 38% within two weeks.

Make your emails mobile-friendly (H3)

• Single column layout (multi-column breaks on phones)
• Minimum 14px font for body text
• Big buttons (at least 44×44 pixels—finger-sized)
• Fast-loading compressed images
• Short paragraphs (2-3 sentences max)
• Clear CTA buttons you can actually tap

Check EVERY email on mobile before sending. Most platforms have preview tools—use them. Or just send yourself a test email and open it on your phone. Takes 30 seconds.

Mistake #4: Trying to do everything in one email

One email. One goal. That’s it.

I see emails trying to:

• Promote new products
• Tell brand story
• Link to blog posts
• Push a sale
• Show the entire catalog

This confuses people. Confused people don’t buy.

One supplement store I worked with was sending product launch emails with 8 different products featured, plus links to their blog, social media, and “shop all.” Click rate: 2.1%. We stripped it down to ONE product with ONE clear CTA. Click rate jumped to 8.7%.

The one-CTA rule (H3)

One objective = one call-to-action. You can have multiple buttons, but they should all lead to the same place.

Big mistake I see constantly: Full website navigation menus at the top of emails. Why? This is an email, not your homepage. Every extra link pulls attention away from your goal.

When people search “what are the common mistakes in email“, multiple CTAs and cluttered designs show up in nearly every top result.

Do this instead:

• Welcome email → All buttons lead to best-sellers
• Product launch → All buttons go to new product
• Re-engagement → All buttons lead to preference center or top categories

Strip everything that doesn’t support your single goal. Research from the Nielsen Norman Group shows single-focus designs convert 2-3x better.

Mistake #5: Your emails are going to spam (and you don’t know it)

Deliverability determines whether your carefully crafted emails reach inboxes or die in spam folders.

Most store owners have no idea their emails are going to spam. I’ve seen stores with 15% open rates wondering why email “doesn’t work” for them. Turns out, 60% of their emails were landing in spam folders. They weren’t measuring deliverability at all.

Stop killing your deliverability

Never buy email lists. Period. It destroys your sender reputation, violates CAN-SPAM regulations, and generates zero real revenue.

I had a store come to Retainful after buying a 50,000 email list. They sent one campaign. Their domain got blocklisted. Took 4 months to recover their sender reputation. Don’t do this.

Authenticate your domain. Set up SPF and DKIM records. Sounds technical, but most email platforms have simple guides. This proves you’re the legitimate sender.

Make unsubscribing easy. Include a clear unsubscribe link in every email. Don’t hide it. Yes, people will leave, but forcing them to stay thanks to your metrics and deliverability.

One store I audited had their unsubscribe link in 8pt gray text at the bottom. People couldn’t find it, so they marked emails as spam instead. Spam complaint rate was 0.4% (anything over 0.1% is bad). We made the unsubscribe obvious. Spam complaints dropped to 0.08%.

Clean your list monthly. Remove bounced emails immediately. Suppress people who haven’t opened anything in 60-90 days.

Fixing already-damaged deliverability

If your emails are landing in spam (check with GlockApps or Mail-Tester):

Step	What to Do	How Long
1	Fix SPF and DKIM authentication	Do now
2	Create “highly engaged” segment (opened in last 7 days)	Do now
3	Send ONLY to engaged segment	30 days
4	Turn on only high-performing flows	30 days
5	Delete bounced emails instantly	Forever
6	Clean unengaged subscribers	Monthly

Spam trigger words to avoid:

• FREE (use “complimentary” or “no cost”)
• URGENT, INSTANT, LIMITED TIME
• Act now, Click here
• 100% guaranteed
• Multiple dollar signs ($$$)
• ALL CAPS ANYTHING

Technical stuff that matters:

• Don’t send one giant image as your entire email
• Keep total email under 102KB
• Balance text and images (60% text, 40% images)

When you search “the rule of 7 in email marketing” or “60 40 rule in email“, you’ll find these ratios mentioned everywhere—because they work.

Mistake #6: Your email flows are way too short

They’re called flows for a reason—they should flow over multiple emails.

Most common mistake? One welcome email and done. You’re leaving so much money on the table.

I see this in probably 70% of new stores joining Retainful. One welcome email saying “Thanks for subscribing!” with maybe a discount code. That’s it. No follow-up. No relationship building. Zero additional sales opportunities.

Why longer flows make more money

Welcome series with 5-7 emails generate 3x more revenue than single emails. Each email gives you another chance to:

• Build trust
• Share customer stories
• Overcome objections
• Make offers
• Show different products

Flow length guide based on data from our stores:

Flow Type	Minimum	Optimal	Timeline
Welcome Series	5 emails	7-10 emails	14-30 days
Abandoned Cart	3 emails	3-4 emails	1-7 days
Post-Purchase	4 emails	5-7 emails	30-60 days
Re-engagement	3 emails	3-5 emails	7-14 days
Browse Abandonment	2 emails	2-3 emails	1-3 days

Longer doesn’t mean spammy—if each email provides value. Monitor your metrics. When open rates tank significantly (usually after email 7-10), end the flow.

Mistake #7: Sending the same email to everyone

Blasting your entire list with identical emails kills engagement fast.

Someone who bought yesterday shouldn’t get the same message as someone who subscribed 6 months ago and never purchased. Different people need different messages.

I audited a fitness equipment store sending the same “20% off everything” email to their entire 28,000-person list. Open rate: 16%. Click rate: 1.2%. We segmented into 5 groups and sent targeted messages. Average open rate jumped to 28%. Click rate to 4.1%.

Why segmentation prints money

Segmented campaigns get 50-100% higher click rates than non-segmented blasts. Plus 30% higher open rates, lower unsubscribes and better deliverability.

When you look at search results for “email automation and segmentation“, every top-ranking article emphasizes this. It’s not a nice-to-have. It’s essential.

Create these 5 segments minimum:

1. Engaged (opened in last 30 days) Your best people. Can handle more frequent emails. At Retainful, we see engaged subscribers convert at 3-5x the rate of general list subscribers.
2. Unengaged (no activity in 60+ days) Send re-engagement campaign, then stop emailing them. They’re hurting your deliverability. One store I worked with had 40% unengaged subscribers. Suppressed them. Overall open rates went from 18% to 31% almost immediately.
3. Customers (made purchases) Focus on repeat purchases, upsells, replenishment. They already trust you. These people convert at 5-7x higher rates than non-buyers.
4. Non-buyers (subscribers only) Need more nurturing, social proof, education before buying. Send them customer testimonials, use cases, educational content.
5. VIP (multiple purchases or high value) Early access, exclusive offers, special treatment. Your most profitable segment. One store gives their VIP segment (top 8% of customers) 48-hour early access to sales. This segment generates 31% of total revenue.

Bonus: Segmentation lets you email more without annoying anyone. Split your list into 5 segments = send 5 emails weekly with each person only getting one.

Mistake #8: Letting your feelings override data

Back to this because it undermines everything.

“I hate marketing emails, so my customers must too.” “Popups hurt user experience.” “Email is outdated—social media is where it’s at.”

I literally had a store owner tell me last month: “I never open marketing emails, so why would my customers?” Meanwhile, their competitors were generating 30% of revenue from email.

Your personal preferences don’t represent your entire customer base.

When you look at Reddit threads about email marketing, you’ll see tons of people claiming “email is dead.” Then in the comments, actual data from people running successful email programs showing $50K, $100K, $200K+ monthly from email alone.

The data doesn’t care about your opinions

Real numbers from actual research:

• $36-40 return per $1 spent on email (Litmus ROI study)
• 68.6% open rate for welcome emails (Constant Contact benchmarks)
• 49% of consumers want weekly promotional emails from brands they like (Statista data)
• Email is 40x more effective for customer acquisition than social (McKinsey research)
• 59% of consumers say marketing emails influence purchase decisions (SaleCycle study)

At Retainful, our top-performing stores generate 25-40% of total revenue from email. Not because they have secret tactics. Because they actually do it properly.

Test like a pro

1. Set up basic flows (welcome, abandoned cart)
2. Create decent lead capture offer
3. Run for 90 days
4. Look at YOUR actual data
5. Decide based on results, not feelings

If properly executed email doesn’t generate positive ROI after 90 days, you have real evidence. But most people quit after 2 weeks because they personally don’t like getting emails.

Mistake #9: Ignoring the easiest wins

Some campaigns are so effective and simple that skipping them is just leaving cash on the table.

I’m always surprised when stores aren’t running these two campaigns. They’re low-hanging fruit that takes maybe an hour to set up.

Back in stock emails

Product sold out? When you restock, email your list immediately.

One clothing store I worked with restocked a popular jacket. Sent one “back in stock” email. Generated $12,400 in 48 hours. One email. 20 minutes to create.

This works because:

• Product already proved demand (it sold out)
• Subscribers likely wanted it
• Scarcity creates urgency (sold out before, might again)
• Takes 10 minutes to set up

Include in your back-in-stock email:

• Clear subject line (“The [Product] Is Back!”)
• Product image
• Why it sold out so fast (social proof)
• Urgent CTA (“Get yours before it’s gone again”)
• Optional: small discount for email subscribers

Product launch campaigns

New products deserve more than one email. Build a proper sequence.

When you see search suggestions like “set up automated email campaigns segmented by lead stage and interests”, product launches are perfect for this. Different segments get different messages.

Launch timeline I use with Retainful stores:

• 7 days before: Teaser (build anticipation)
• 5 days before: Sneak peek (show features)
• 3 days before: VIP early access (best customers only)
• Launch day: Official announcement
• 2-3 days after: Last chance (create urgency)

VIP early access is magic:

• Give customers 24-48 hour head start
• Create scarcity (“Only 200 units for early access”)
• Build exclusivity (“You’re getting first dibs”)
• Result: Higher engagement, more revenue, stronger relationships

Coordinate with social media. Drive traffic to landing page with email capture focused on the launch. Studies show coordinated launches perform 3x better.

Your 4-week fix-it plan

Feeling overwhelmed? Here’s what to do first:

Week 1: Fix the foundation

• Set up domain authentication (SPF and DKIM)
• Create 5 basic segments (engaged, unengaged, buyers, non-buyers, VIP)
• Install exit-intent popup with strong offer

Week 2-3: Build core flows 4. 5-email welcome series 5. 3-email abandoned cart sequence 6. 2-email browse abandonment flow

Week 4: Optimize 7. Mobile-optimize all templates 8. Clean your list (bounces + unengaged) 9. Test different popup offers (discount vs. gift vs. free shipping)

Every month after: 10. Clean your list 11. Test new campaigns 12. Track metrics (opens, clicks, revenue per email)

I’ve seen stores implement this exact plan and go from $2K/month email revenue to $15K+ in 60 days. No magic. Just fixing the obvious stuff.

Stop leaving money on the table

These email mistakes aren’t small issues—they’re killing thousands of dollars in revenue every month.

In my daily audits at Retainful, I see stores with massive potential leaving 30-40% of possible revenue on the table because of these nine mistakes. The the best part? Most are fixable in a weekend.

Good news? Everything’s fixable. You don’t need a massive budget or complex tech. You need to:

• Stop letting personal bias override proven $36-40 ROI data
• Set up proper lead capture that trades real value
• Build longer flows that actually nurture relationships
• Segment your list so messages stay relevant
• Make everything work on mobile
• Check deliverability monthly
• Run back-in-stock and launch campaigns

Email marketing delivers better ROI than almost any other channel. The question isn’t whether it works—it’s whether you’ll do it right.

Ready to fix your email marketing? Retainful makes it simple with pre-built automation, cart recovery, and proven templates designed for e-commerce stores. We’ve helped over 20,000 stores turn email into their most profitable channel. Start free or see how it works to turn your email list into consistent revenue.

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