Email marketing KPIs

Email has a dozen possible metrics. Focus on the ones that map to business outcomes.

Core KPIs

• Open rate (20-40% broadcast, 40-60% transactional)
• Click-through rate (1-5% broadcast, 10%+ highly-targeted)
• Conversion rate (varies wildly)
• Unsubscribe rate (<0.5%)
• Spam complaints (<0.1%)
• List growth rate

Revenue KPIs

• Revenue per email sent (RPES)
• Revenue per subscriber per month
• List LTV

Post-iOS 15 open rates

Apple's Mail Privacy Protection pre-loads images, inflating opens by 20-40%. Open rates are less reliable than they were; click rate is truer.

What to do with this

• Track revenue per email sent as the primary KPI, open rate is now inflated by iOS prefetching and no longer a reliable signal
• Measure click rate as your true engagement signal, subscribers clicking prove interest in a way opens no longer do
• Compute revenue per subscriber monthly, declining RPS means list quality is degrading even if list size grows
• Segment KPIs by campaign type (welcome vs broadcast vs promo), blending them hides which flows carry the revenue
• Set KPI targets vs industry benchmarks, not internal comparisons, internal improvement against bad baseline still loses to category average