Definition
Email revenue per thousand subscribers measures how much revenue is generated for every 1,000 active subscribers on a list. It normalises total email-attributed revenue to a fixed subscriber base, allowing senders to compare the value of lists of different sizes, or to track their own list's productivity over time. The metric is a standardised cousin of revenue-per-subscriber.
How It Works
Because lists vary widely in size, raw revenue is hard to compare. Revenue per thousand subscribers removes that variable by expressing value on a common per-1,000 basis, similar to how advertisers use cost per mille (CPM).
- Normalisation — dividing by active subscribers and multiplying by 1,000 yields a stable, comparable rate.
- List quality signal — the metric reflects both list engagement and monetisation, since a large but disengaged list produces less revenue per thousand than a small, engaged one.
- Trend tracking — monitoring the figure over time reveals whether list value is improving or eroding.
This metric is especially useful when benchmarking against industry norms or when evaluating the return on list-building investments.
How to Calculate
Calculate revenue per thousand subscribers in three steps:
- Sum attributed revenue — total the revenue credited to email over the period.
- Count active subscribers — determine the number of active subscribers on the list.
- Divide and scale — divide revenue by subscribers, then multiply by 1,000.
Revenue Per 1,000 Subscribers = (Total Attributed Revenue / Active Subscribers) x 1000
| Variable | Description |
|---|---|
| Total Attributed Revenue | Revenue generated from email over the period |
| Active Subscribers | Number of active subscribers on the list |
Example
A brand with 40,000 active subscribers generates £24,000 in email-attributed revenue in a month. Dividing £24,000 by 40,000 gives £0.60 per subscriber, and multiplying by 1,000 gives £600 per thousand subscribers. The team uses this figure to compare against the prior month's £540 and to benchmark its list against peers.
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Frequently Asked Questions
Revenue-per-subscriber expresses value per single subscriber, while revenue per thousand subscribers expresses it per 1,000. The two carry identical information at different scales; the per-thousand form is convenient for comparing against CPM-style benchmarks.
Expressing value per thousand makes differences easier to read and aligns email metrics with common advertising cost conventions. It avoids long decimals that arise from per-subscriber figures.
Use active subscribers for a realistic picture of list value. Including disengaged or suppressed subscribers inflates the denominator and understates the productivity of the subscribers who actually receive and respond to email.
A decline suggests list value is falling, either because new subscribers are less engaged, monetisation is weakening, or the list is growing faster than revenue. Investigating the underlying cause guides corrective action.