Beyond Open Rate: The 7 Metrics That Actually Predict Email Revenue

The seven metrics that actually correlate with email-attributed revenue are: Revenue Per Subscriber (RPS), Engagement Decay Rate, Send-Time Elasticity, List Health Score, Click Depth Index, Re-engagement Response Rate, and Churn Prediction Signal.

Revenue Per Subscriber is the North Star. A list of 10,000 engaged subscribers generating $4.50 RPS will always outperform a list of 100,000 with a $0.12 RPS. The goal isn't a big list — it's a valuable one. Calculate it monthly: total email-attributed revenue ÷ total active subscribers.

Engagement Decay Rate measures how quickly a subscriber's engagement drops off after joining. A healthy list shows a decay curve that flattens after week four as engaged subscribers stabilize. A list with ongoing decay means your onboarding sequence isn't establishing the habit.

Send-Time Elasticity tells you how sensitive your audience's open rate is to changes in send time. A high-elasticity audience (early-stage B2B buyers) responds dramatically differently to Tuesday vs. Thursday sends. Low-elasticity audiences (daily newsletter readers) barely notice. Knowing your elasticity tells you how much time to invest in send-time optimization.

The remaining three — List Health Score, Click Depth Index, and Churn Prediction Signal — are leading indicators. They tell you what your revenue will look like in 90 days, not what it looked like last month. MailMind's dashboard surfaces all seven automatically so you can catch problems before they show up in revenue.