Deliverability · 3 min read
What Better Deliverability Is Worth to You
Small gains in open rate and inbox placement compound into measurable revenue. This is not about fixing broken campaigns; it is about quantifying what better performance is actually worth.
The success of an email campaign is usually judged on a set of numbers - the percentage that gets delivered, the fraction that actually gets opened, and the subset of opens that turn into clicks and then conversions.
Improving any one of those numbers by a few points is worth significant money over time, and the math is straightforward enough to calculate for your own specific situation.
The leverage points
These metrics move the needle on email revenue:
Open rate: if 30 per cent of your sends end up in the spam folder, you have already lost 30 per cent of potential engagement before anyone reads a single word. Authentication issues, sender reputation problems or bad list hygiene can all contribute.
Click-through rate: once in the inbox, does the content compel action? A two-percentage-point lift on click rate translates directly into more conversions, assuming the audience and offer are the same.
Volume and frequency: this does not mean purchasing a list and spamming it every day. But, for a healthy list, volume and frequency matter. More isn’t usually best even with opt-in lists; every list has a sweet spot.
The compounding effect
The arithmetic of email is multiplicative, not additive. Suppose your campaign reaches 10,000 subscribers with a 20 per cent open rate and 3 per cent click rate:
- Opens: 2,000 messages seen
- Clicks: 60 recipients engaged
Now raise the open rate to 25 per cent through better deliverability:
- Opens: 2,500 messages seen
- Clicks: 75 recipients engaged (assuming constant click rate)
That is a 25 per cent increase in engagement from a five-point lift in open rate. If each click converts at 2 per cent into sales worth £50:
- Before: 60 × 2 per cent × £50 = £600 revenue
- After: 75 × 2 per cent × £50 = £750 revenue
A five-point delivery improvement yielded £150 extra on this campaign alone. Multiply that across monthly sends and the value compounds.
What gets measured gets fixed
The hardest part is establishing a baseline. Without knowing your current open rate and conversion numbers, any claim about potential improvement is speculation. With those numbers in hand, the calculation becomes transparent.
The most common blind spots:
- Untracked conversion attribution: email clicks that lead to purchases several days later frequently get credited to other channels
- Missing segmentation data: aggregated metrics hide which segments underperform and why
- Fixing on open rate: MPP, for example, inflates opens. True open rate is largely unknown; clicks and conversions are better metrics to focus on.
Calculate your own numbers
The ROI calculator below lets you enter your current campaign metrics and estimate what small improvements would be worth. You control the inputs, so the results reflect your own business rather than industry averages that may not apply.
One caveat: the calculator shows potential, not certainty. Deliverability fixes cannot compensate for fundamentally weak offers or poor content quality. But they do remove obstacles that prevent good mail from reaching the people who care about it.
The realistic ceiling
There is no universal benchmark for “good” email performance. Industry averages vary wildly by sector, audience sophistication and list quality. What matters is your trajectory: are you improving from your current baseline, or drifting downward while competitors pull ahead?
For businesses that send regularly, even incremental progress adds up. The question is not whether better email performance is valuable. It is how much it is worth to your organisation specifically, and whether the investment required to achieve it is justified.
That answer depends entirely on your own numbers.