Definition
Email ARPU (Average Revenue Per User, applied specifically to email) measures the average revenue generated per active subscriber through email-attributed activity over a given period. It divides total email-attributed revenue by the number of active subscribers, quantifying how much each subscriber on the list is worth. Email ARPU is a core measure of list value and campaign effectiveness.
How It Works
Email ARPU focuses the broader ARPU concept specifically on revenue driven by email, distinguishing it from revenue earned through other channels.
- Email-attributed revenue — only revenue credited to email campaigns and flows is counted, using an attribution window consistent with the business.
- Active subscriber base — the denominator is active subscribers, typically those engaged within a recent window, rather than the entire raw list.
- Value signal — email ARPU rises when email becomes more effective at monetising the list, and falls when engagement or offer strength declines.
Email ARPU is closely related to arpu and revenue-per-subscriber. The key distinction is that email ARPU attributes revenue specifically to email, whereas general ARPU may include all channel revenue per subscriber.
How to Calculate
Calculate email ARPU in three steps:
- Sum email-attributed revenue — total the revenue credited to email in the period.
- Count active subscribers — determine the number of active subscribers on the list.
- Divide — divide email-attributed revenue by active subscribers.
Email ARPU = Email-Attributed Revenue / Number of Active Subscribers
| Variable | Description |
|---|---|
| Email-Attributed Revenue | Revenue credited to email activity in the period |
| Active Subscribers | Number of active subscribers on the list |
Example
A brand attributes £90,000 in monthly revenue to email and has 30,000 active subscribers. Dividing £90,000 by 30,000 gives an email ARPU of £3.00 per subscriber per month. The brand tracks this figure monthly and uses it to forecast the value of growing the list.
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Frequently Asked Questions
General arpu divides all revenue by subscriber count regardless of channel, while email ARPU divides only email-attributed revenue by active subscribers. Email ARPU isolates the email channel's specific contribution.
Use active subscribers. Including disengaged or suppressed addresses inflates the denominator and understates the value of the subscribers who actually receive and respond to email.
Improving targeting and personalisation, increasing conversion-rate, and driving higher-value purchases all raise email ARPU. Reducing list churn among high-value subscribers also helps.
Monthly is the most common cadence, with quarterly views for strategic analysis. Monthly measurement captures campaign trends, while quarterly views smooth out seasonal variation.