Your email marketing might be delivering £38 for every pound spent, but if you're still obsessing over open rates, you're measuring success with a broken ruler.
The average ROI for marketing emails in the US and UK is between 3600% and 3800%, with UK companies specifically achieving £38 return for every £1 invested according to the DMA. Yet most UK SMEs are tracking metrics that tell them nothing about actual profitability.
Here's what's changed in 2026, and why your current dashboard is probably lying to you.
Why Open Rates Are Dead (But Nobody Told Your Marketing Team)
Open rates served as the north star metric for decades. In 2026, they've become one of the least reliable indicators of email success due to Apple Mail Privacy Protection and similar features in other clients that pre-load images and inflate open counts.
When Apple introduced Mail Privacy Protection, it didn't just tweak the system – it fundamentally broke open rate tracking. Your "30% open rate" might include thousands of emails that were never actually seen by humans.
If you're still using open rates as your primary success metric, you're optimising for ghost engagement. Time to find metrics that actually correlate with revenue.
Metrics like CTR, conversion rate, unsubscribe rate, revenue per email (RPE), and email marketing ROI provide a more holistic view of performance, over open rate. Smart marketers have already made the switch.
The Metrics UK SMEs Should Actually Track
Revenue Per Email (RPE): Your New North Star
The average value of a customer email address in the UK is £36.64, but this varies massively by industry and how well you're executing. RPE cuts through vanity metrics and shows you exactly how much each campaign contributes to your bottom line.
Calculate it simply: Total revenue generated ÷ Total emails sent = RPE
A good UK SME should aim for 15-25p per email sent, depending on their industry.
Click-to-Conversion Rate: The Engagement Reality Check
15.22% of click-throughs from email convert, whilst the overall conversion rate for all emails sent is 1.06%. This metric tells you whether people who engage with your emails actually buy from you.
Email campaign click-to-conversion rates grew by 27.6% in 2024, showing that consumers who engage with emails are increasingly likely to make purchases after clicking through. If your conversion rate is falling, your content might be attracting clicks but not qualified buyers.
List Growth Rate vs Churn
Here's what most UK SMEs miss: campaigns targeting fewer than 50 recipients have an average reply rate of 5.8%, compared to 2.1% for campaigns with over 1,000 recipients, highlighting the benefit of smaller, segmented lists.
Quality beats quantity every time. A 1,000-person list of engaged customers will outperform a 10,000-person list of cold contacts.
Industry Benchmarks UK SMEs Need to Know
The highest converting industry in 2024 was games (0.30%), followed by auto and vehicles (0.23%) and arts and entertainment (0.18%). Looking at specific category performance, books and literature (29.4%), sports (28.8%), food and drink (26.1%), and travel (28.2%) all achieved open rates above 25%.
Benchmark Against Your Sector
Don't compare your plumbing business metrics against e-commerce averages. Industry context matters for realistic target setting.
Focus on Trend Direction
A 20% open rate that's growing is better than a 25% open rate that's declining. Look at 3-month trends, not single campaign performance.
Correlate with Revenue
Only metrics that correlate with actual revenue deserve space on your dashboard. Everything else is just noise.
The AI Impact on Email Metrics in 2026
In 2025, 49% of marketers use generative AI for static copy creation in emails, and marketers predict that up to 75% of their email operations will be AI-driven by the end of 2026.
AI isn't just changing how we create emails – it's changing how we should measure them. Email is entering a new era powered by intelligent inboxes, predictive AI, and authentication directly supporting AI-driven personalization and dynamic content.
This means your metrics need to account for:
- Personalisation effectiveness per segment
- Automated workflow performance
- Predictive engagement scoring
- Cross-channel attribution
What This Means for Your Dashboard
41% of best-in-class email marketers use conversion rate as their primary KPI, not open rates or even click-through rates.
Your 2026 email marketing dashboard should show:
Primary Metrics:
- Revenue per email (RPE)
- Conversion rate by segment
- Customer lifetime value from email subscribers
- List growth rate (quality-adjusted)
Secondary Metrics:
- Click-to-conversion rate
- Unsubscribe rate
- Spam complaint rate
- Engagement trend over time
Forget These:
- Overall open rates (use segmented engagement scores instead)
- Total list size (without quality context)
- Emails sent (volume doesn't equal success)
Set up a monthly review where you only look at metrics that directly correlate with revenue. If a metric doesn't help you decide what to do differently, stop tracking it.
The ROI Reality Check
18% of companies report an email marketing ROI greater than 7000%, and 63% of organisations that get a high ROI from email marketing spend more than 20% of their marketing budget on it.
The difference between average and exceptional email marketing ROI often comes down to measurement discipline. Companies tracking the right metrics make better decisions, which compounds into significantly better results.
Getting Started: Your 30-Day Action Plan
Most UK SMEs can improve their email marketing ROI by 40-60% just by measuring the right things and acting on the data.
Start by auditing your current metrics against revenue correlation. If you're spending time tracking metrics that don't predict sales, you're optimising for the wrong outcomes.
The companies seeing impressive ROI of $68 for each dollar spent – approximately double the average for email marketing aren't necessarily sending better emails. They're just measuring and optimising for what actually matters: profitable customer actions.
Your email marketing budget and strategy should be driven by revenue metrics, not engagement theatre. Make the switch now, before your competitors figure out what you're missing.
Want help setting up proper email marketing measurement for your UK business? Contact our automation team to discuss how we can help you track what actually drives growth, or explore our business intelligence solutions to get better visibility into your marketing ROI across all channels.