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Estd 4.22.2023
Introduction
In today's digital landscape, email remains one of the most powerful channels for SaaS companies. With an average ROI of $42 for every $1 spent according to the Data & Marketing Association, email marketing continues to outperform other digital marketing channels. However, this effectiveness is only realized when properly measured and optimized.
For SaaS executives, understanding email marketing metrics isn't just about tracking opens and clicks—it's about connecting these metrics to revenue growth, customer retention, and business objectives. This guide will walk you through the essential email marketing metrics for SaaS companies and how to calculate them to drive data-informed decisions.
Key Email Marketing Metrics for SaaS
1. Delivery Rate
What it measures: The percentage of emails that successfully reached recipients' inboxes.
How to calculate:
Delivery Rate = (Number of emails delivered ÷ Number of emails sent) × 100Why it matters: A low delivery rate indicates potential issues with your email infrastructure, list quality, or sender reputation. According to Campaign Monitor, the average delivery rate across industries is 98%. If yours falls below 95%, it's time to investigate.
2. Open Rate
What it measures: The percentage of delivered emails that were opened.
How to calculate:
Open Rate = (Number of emails opened ÷ Number of emails delivered) × 100Why it matters: Open rates indicate the effectiveness of your subject lines and sender reputation. The average open rate for SaaS companies is around 21%, according to Mailchimp's benchmark reports. However, with Apple's Mail Privacy Protection now hiding some opens, this metric should be viewed as comparative rather than absolute.
3. Click-Through Rate (CTR)
What it measures: The percentage of email recipients who clicked on at least one link in your email.
How to calculate:
CTR = (Number of unique clicks ÷ Number of delivered emails) × 100Why it matters: CTR measures the relevance and appeal of your content. For SaaS, average CTRs hover around 2.5%, but successful targeted campaigns can reach 5-10%.
4. Click-to-Open Rate (CTOR)
What it measures: The ratio of unique clicks to unique opens.
How to calculate:
CTOR = (Number of unique clicks ÷ Number of unique opens) × 100Why it matters: CTOR helps isolate content performance from subject line effectiveness. It shows whether people who opened your email found the content compelling enough to click. For SaaS, aim for CTORs above 20%.
SaaS-Specific Email Marketing Metrics
5. Conversion Rate
What it measures: The percentage of email recipients who completed a desired action (trial signup, demo request, purchase, etc.).
How to calculate:
Conversion Rate = (Number of conversions ÷ Number of delivered emails) × 100Why it matters: This directly ties your email efforts to business outcomes. According to Acoustic's benchmark data, the average conversion rate from email campaigns ranges from 1-3% for SaaS companies.
6. Revenue Per Email (RPE)
What it measures: The average revenue generated from each email sent.
How to calculate:
RPE = Total revenue generated from campaign ÷ Number of emails sentWhy it matters: RPE helps quantify the direct financial impact of your email marketing. For subscription-based SaaS companies, this metric should account for the customer lifetime value (LTV) influenced by email campaigns.
7. Email Customer Acquisition Cost (CAC)
What it measures: The cost to acquire a customer through email marketing.
How to calculate:
Email CAC = Total email campaign costs ÷ Number of new customers acquired through emailWhy it matters: For SaaS executives, this metric allows you to compare the efficiency of email against other acquisition channels. Research from ProfitWell indicates that email typically has a lower CAC than paid advertising channels.
8. Churn Rate Influenced by Email
What it measures: How email engagement correlates with customer retention.
How to calculate:
Compare churn rates between engaged email subscribers vs. non-engaged subscribersWhy it matters: Research from Customer.io shows that SaaS customers who engage with email communications have 23% higher retention rates than those who don't.
Advanced SaaS Email Metrics
9. Product Adoption Rate from Email
What it measures: The percentage of users who adopt specific features after being prompted by email.
How to calculate:
Feature Adoption Rate = (Number of users who used feature after email ÷ Number of users who received feature announcement email) × 100Why it matters: This connects your email marketing directly to product usage. According to Appcues, feature announcement emails that drive adoption can increase overall product stickiness by up to 30%.
10. Email Engagement Score
What it measures: A composite score that weighs different engagement actions.
How to calculate:
Assign point values to different actions (e.g., open = 1 point, click = 3 points, conversion = 10 points), then calculate the average per subscriberWhy it matters: This creates a single metric for overall engagement that can be tracked over time and across segments. Companies using engagement scoring see up to 22% higher retention rates, according to research from Totango.
Turning Metrics Into Action
Segmentation Performance
Compare key metrics across different customer segments:
- By customer life cycle (prospect, trial, active customer, at-risk)
- By product usage patterns (power users vs. occasional users)
- By plan/tier (enterprise vs. SMB vs. individual)
A/B Testing Analysis
When running A/B tests on your emails:
- Calculate statistical significance using this formula:
Z-Score = (Conversion Rate B - Conversion Rate A) ÷ Square Root[(Standard Error A² + Standard Error B²)]- A Z-Score greater than 1.96 indicates a statistically significant difference with 95% confidence.
Implementation Roadmap
- Crawl: Start by tracking delivery rate, open rate, CTR, and conversion rate for all campaigns
- Walk: Implement segmentation analysis and introduce RPE and CAC calculations
- Run: Deploy more advanced metrics like engagement scoring and product adoption tracking
- Fly: Integrate email metrics with overall customer journey analytics and predictive modeling
Conclusion
For SaaS executives, email marketing metrics need to go beyond surface-level engagement to demonstrate real business impact. By tracking the right metrics in this guide, you can connect email performance directly to revenue growth, customer retention, and product adoption.
The most successful SaaS companies aren't necessarily those sending the most emails—they're the ones systematically measuring results and optimizing based on data. Start with the fundamentals, gradually introduce more sophisticated metrics, and continuously test to improve performance.
Remember that context matters—your metrics should always be compared against your historical performance, industry benchmarks, and business objectives. When properly measured and analyzed, email marketing can be one of the most powerful and cost-effective tools in your SaaS growth arsenal.