4 Email Marketing Metrics That Actually Drive Performance (Not Just Opens)
Knowing your email marketing metrics can make or break your ROI. Open rates and click-through rates get a lot of attention—but they don't paint the full picture.
Someone opened your email—then what? Did they click? Did they buy? Did they scroll, or did they send it to the trash?
You can’t grow your email strategy by focusing on clicks alone. If you want real results, you need data that goes deeper. Here are four metrics that reveal how your campaigns truly perform.
1. Revenue per Email (RPE): The Ultimate Email Marketing ROI Metric
Some emails rake in sales. Others just clutter inboxes.
Revenue per email (RPE) is the metric that cuts through the noise and tells you exactly how much money your emails are earning. On average, email marketing delivers $36 for every $1 spent.
Want to boost RPE? Start with these:
Segment your list: Personalized offers to repeat buyers can dramatically improve results.
Test everything: Small tweaks to CTAs or subject lines can boost both clicks and revenue.
2. Click-to-Conversion Rate: From Interest to Revenue
Clicks mean interest. Conversions mean revenue.
This metric tracks how many people who click your email actually complete a purchase (or other key action). If your rate is low, something’s off—either your offer doesn’t hit hard enough, or your landing page is out of sync with the email.
Here’s the fix: Make sure your landing page delivers on what the email promises. If you tease an exclusive deal, your customer shouldn’t have to search for it. Keep the path to conversion smooth.
3. Unsubscribe Rate: Measuring Email List Health
You don’t just need a growing email list—you need one that sticks around.
Your unsubscribe rate reveals whether your audience is staying or slipping away. If your unsub rate is rising, you might be missing the mark with irrelevant content or too-frequent sends.
How do you reduce unsubscribes?
Let your subscribers choose their preferences. Give them control over how often they hear from you and what kind of content they get. When you send them content they care about, they’re less likely to hit “unsubscribe.”
Research shows personalized email experiences reduce churn by 26%.
4. Customer Lifetime Value (CLV): The Long-Term Email Marketing Win
CLV measures how much revenue a customer generates over time. While it’s not an email-specific metric, email is crucial for maximizing CLV by nurturing high-value customers through ongoing engagement.
Brands that obsess over CLV don’t just keep customers—they grow profits. Companies that prioritize retention can increase profitability by up to 95%.
💡 Retention tip: Stay in front of your best customers with post-purchase email flows. Offer them early access, exclusive discounts, or curated recommendations based on their purchase history.
Here’s what matters
Open and click rates are just surface metrics. The real drivers of success are:
Revenue per Email: Track how much each email earns.
Click-to-Conversion Rate: Measure how well your clicks turn into sales.
Subscriber Retention: Keep your list engaged and growing.
Customer Lifetime Value: Long-term revenue from loyal buyers.
These email marketing metrics tell the true story of your campaigns—and they'll help you grow your revenue, predictably and sustainably.
Ready to Grow your Revenue?
Let’s uncover the opportunities hiding in your email data. Schedule a call with 624 Agency today!
F.A.Q.s
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A strong RPE varies by industry, but as a benchmark, aim for at least $0.10 to $0.50 per email sent. E-commerce brands often see higher rates, especially during promotional periods. The key is to track your RPE over time and look for consistent growth. If your RPE is declining, it's time to revisit your segmentation strategy and offer relevance.
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Click-to-conversion rate = (Number of conversions / Number of clicks) × 100
For example, if 100 people clicked your email and 15 made a purchase, your click-to-conversion rate is 15%. This metric is crucial because it shows how effective your email message is at driving actual business results, not just engagement.
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Most healthy email lists see unsubscribe rates between 0.2% and 0.5% per campaign. If you're consistently above 0.5%, you may be sending too frequently, targeting the wrong audience, or delivering irrelevant content. A spike after a specific campaign can signal a mismatch between subscriber expectations and what you delivered.
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CLV helps you understand which customers are worth investing in through email nurture campaigns. When you know a customer segment has a high CLV, you can justify spending more on personalized content, exclusive offers, and retention campaigns for that group. Email is one of the most cost-effective channels for increasing CLV because it allows you to stay consistently connected with your best customers.