Email marketing consistently delivers the highest ROI of any digital channel, with Australian businesses seeing an average return of $42 for every $1 spent. Yet most marketers focus on the wrong metrics. Open rates and click-through rates tell you how your emails perform in isolation — they don't tell you whether email is driving revenue.
This guide covers the 7 email marketing metrics that actually matter for Australian businesses, how to benchmark them, and how to improve each one systematically.
Vanity vs. Actionable Metrics
Before diving into the numbers, it's important to distinguish between vanity metrics and actionable ones:
- Open rate — Vanity. It can be inflated by subject line tricks, preview text, and Apple's Mail Privacy Protection (which now inflates open rates across the board).
- Click-through rate — Better but incomplete. A high CTR means nothing if those clicks don't convert.
- Conversion rate — Actionable. This correlates directly with revenue and should be your primary north-star metric.
- Revenue per email — The single most important metric. It captures everything — list quality, offer relevance, timing, and creative effectiveness — in one number.
The 7 Essential Metrics
1. Conversion Rate per Subscriber
This measures the percentage of subscribers who complete a desired action (purchase, signup, download) from an email campaign. A healthy conversion rate for Australian e-commerce email campaigns is 2-5%, though this varies significantly by industry. Track it per campaign and per segment to identify what resonates.
2. Revenue per Email
Revenue per email sent is your true north metric. It tells you exactly how much money each email generates, accounting for list size, deliverability, and conversion effectiveness. For most Australian businesses, a revenue per email of $0.10-$0.50 is solid, with top performers exceeding $1.00.
3. List Growth Rate
Your email list naturally decays at 20-30% per year due to churn, inactivity, and bounces. A healthy list growth rate should exceed your churn rate. Aim for 3-5% net monthly growth through lead magnets, popup forms, and content upgrades.
4. Email Sharing and Forwarding Rate
This measures how many recipients forward your email or click a "share" link. A rate above 1% indicates you are creating content valuable enough to share — a strong signal for list growth and brand advocacy.
5. Unsubscribe Rate
An unsubscribe rate below 0.5% is healthy. Spikes above 1% indicate frequency or relevance problems. Monitor this per campaign and per segment. If a particular segment is unsubscribing at high rates, reduce frequency or adjust content.
6. Spam Complaint Rate
This is your most important compliance metric. The ATO and ACMA regulate commercial email under the Spam Act 2003. A complaint rate above 0.1% can get your domain blacklisted and harm deliverability across all campaigns. If you exceed 0.1%, pause sends immediately and review your list acquisition and permission practices.
7. Customer Lifetime Value by Segment
Emails sent to existing customers generate 3-5x more revenue than emails to prospects. Track CLV by acquisition channel and segment to understand which email strategies drive the most long-term value.
Benchmarking Your Performance
For Australian email marketing in 2025, here are the key benchmarks:
- Open rate: 20-25% (note: Apple MPP inflates this by 5-10%)
- Click-through rate: 2.5-4%
- Click-to-open rate (CTOR): 10-15%
- Conversion rate: 2-5%
- Unsubscribe rate: <0.3%
- Spam complaint rate: <0.05%
These benchmarks vary by industry. Financial services typically sees lower open rates (15-20%) but higher conversion rates. Retail sees higher open rates (25-35%) but lower conversion rates.
Optimization Framework
Improving email marketing metrics requires a systematic testing program. Use this framework:
- Audience: Segment by engagement level (active vs. lapsed), purchase history, and demographics
- Subject line: A/B test length, personalisation, and urgency
- Content: Test educational vs. promotional balance
- CTA: Test button colour, copy, and placement
- Timing: Test day of week and time of day
- Frequency: Monitor unsubscribe rates as you increase sends
Run one test per week and track the impact on revenue per email. A compounding improvement of 1% per week results in a 67% annual improvement.
Conclusion
Stop obsessing over open rates and start tracking revenue per email, conversion rate, and customer lifetime value. These three metrics tell you whether your email program is actually growing your business. Compliance matters too — keeping spam complaints below 0.05% protects your deliverability.
Optimise your email campaigns with the BizMetrixs analytics calculators to ensure you're tracking the metrics that matter.