Definition
Campaign IRR is a financial metric that calculates the annualised return of an email campaign, considering when costs occur and when revenue arrives. It is more sophisticated than standard ROI because it accounts for the time value of money.
Why It Matters
Standard ROI treats all money equally regardless of timing. A campaign that costs £1,000 in January and generates £5,000 spread across six months has a different financial profile from a campaign that generates £5,000 in the first week. IRR captures this difference. It is most useful for comparing email investment efficiency against other channels or financial benchmarks.
Limitations
IRR is a useful internal comparison metric but requires accurate cost and revenue timing data. Most email marketers find simpler metrics like ROI, payback period, and channel margin more practical for day-to-day campaign evaluation.
Related Glossary Terms
A/B Testing
A/B testing in email marketing is the practice of sending two variations of an email to a small sample of your list to determine which version performs better before sending the winner to the remaining subscribers.
ARPU (Average Revenue Per User)
ARPU (Average Revenue Per User) is a metric that measures the average revenue generated per email subscriber over a specific period, used to evaluate list value and campaign effectiveness.
Attention Rate
Attention rate is the percentage of email opens that last longer than 5 seconds, distinguishing genuine reads from passive opens, preview-pane views, or Apple MPP auto-loads.
Bounce Rate
Email bounce rate is the percentage of emails that were rejected by the receiving server before reaching the recipient. It is a key indicator of list health and data quality.
Campaign Lifted Revenue
Campaign lifted revenue is the additional revenue generated by an email campaign beyond what would have occurred without it, measured via a holdout group or statistical lift analysis.
Campaign Payback Period (Email)
The campaign payback period is the number of sales or amount of revenue needed to recover the full cost of creating, producing, and sending an email campaign.