THE SITUATION
Blue Horizon had a large email list and a channel doing almost nothing. Email generated 5% of total revenue. Roughly 90% of the list was unengaged — no open, no click, in 90+ days. Open rates sat at 21.9%, click rates at 2.5%. Deliverability was weak enough that a meaningful share of sends weren’t reaching the inbox at all.
Two automated flows existed. Tens of thousands of subscribers had never purchased and had no dedicated path to convert them.
This wasn’t a content problem. It was an architecture problem — the channel had no structural foundation for retention to compound on.
THE GAP
A list that large generating 5% of revenue isn’t underperforming by a little. The non-purchaser segment alone — subscribers who’d opted in but never bought — represented a quantifiable revenue opportunity sitting untouched. Modelled against AOV, even converting a low single-digit percentage of that segment was a material number. The brand was paying to hold and email an audience it had no system to convert.
THE ENGINEERING
An unengaged list isn’t just a low-open-rate problem — it actively suppresses inbox placement for the engaged subscribers too. Unengaged contacts were systematically cleaned and a deliverability recovery was run from the ground up. Inbox placement was rebuilt month over month until the deliverability score reached 80. Open rates moved to as high as 66%, click rates to 7.25%. This is the precondition for everything else: retention can’t compound through a channel that doesn’t reach the inbox.
The tens of thousands of subscribers who had never bought were treated as a distinct segment with its own engineered path — not folded into the general send. This is the RE principle applied directly: different customer relationships require structurally different journeys. The non-purchaser segment got a system built specifically to convert it, and it became a primary driver of the contribution shift inside the first 90 days.
Two flows became a full automated stack. Critically, the flows were segmented by purchase behaviour and engagement depth — so the message, timing, and offer changed based on where the subscriber actually was in their relationship with the brand, rather than everyone receiving the same sequence. Welcome, post-purchase, and checkout flows were rebuilt around behavioural triggers rather than generic timing.
THE RESULTS
Revenue within 90 days
Email revenue contribution grew from 5% to 30% of total revenue within 90 days
£950k generated from email and SMS in 2025
Open rates rose from 21.9% to as high as 66%
Click rates rose from 2.5% to 7.25%
Deliverability score rebuilt to 80 within the first months of the engagement
A previously dormant non-purchaser segment converted into a recurring revenue contributor
FULL VIDEO TESTIMONIAL
Paul Harris, Blue Horizon — full video testimonial
THE LINE THAT MATTERS
"A list generating 5% of revenue became a system generating 30% — and £950k a year — by engineering the architecture underneath it, not by sending more email."
