Marketing data & attribution consulting
Your campaigns probably aren't the problem. Your data is.
Your agency optimises campaigns against the numbers they're given. I make sure those numbers are correct — fixing the identity, tracking, and attribution layer underneath your marketing so the decisions built on top of it actually hold up.
Attribution that doesn't add up
First-click, last-click, and platform-reported numbers all disagree — and nobody can say which one is right.
"New" customers who aren't new
Broken identity stitching across devices and sessions inflates acquisition numbers and hides real retention.
Spend decisions on guesswork
Budget gets moved between channels based on dashboards nobody has actually validated against reality.
How it works
Five phases, start wherever it makes sense
Most engagements start with the audit and stop there, or continue phase by phase as issues are found. Nothing is sold as a bundle up front.
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01
Data & Attribution Audit
A fixed-price diagnostic. I map your existing tracking, find the gaps and errors, and hand you a findings report with a prioritised roadmap — no commitment beyond this.
£3k – £8k -
02
Identity & Tracking Foundation
Stitching users across GA4 user IDs, session IDs, canonical IDs, and event platforms like Snowplow, with heuristic probabilistic matching, so new-vs-returning classification is actually accurate.
£5k – £15k -
03
Customer Behaviour Modelling
Conversion curves, cohort survival analysis, and funnel drop-off modelling — a real model of how customers move through your funnel, not a dashboard estimate.
£8k – £20k -
04
Attribution Modelling
Shapley value attribution and regression-based modelling of paid impact on non-paid channels, benchmarked against your existing first/last-touch numbers.
£8k – £20k -
05
Ongoing Retainer
Monthly attribution refresh, funnel health monitoring, and anomaly detection — so drift gets caught before it costs you a quarter of misallocated spend.
£1.5k – £3k / month
About
I've sat inside the agencies doing the optimising.
I'm Damien Harley, a data and analytics engineer based in Hull, UK. I've built and shipped a full SaaS product solo, end to end, and spent years working as a data engineering contractor inside multiple marketing agencies.
Every time, the pattern was the same: the agency was optimising campaigns with real skill, against measurement nobody had actually verified. Attribution models built on identity data that was quietly broken. "New customer" numbers that weren't new. Nobody's fault directly — it's just not the agency's job to audit the pipes, and it's not always obvious anything is wrong.
That's the gap I work in now: the layer underneath the campaigns, not the campaigns themselves.
Get in touch
Start with a straight answer.
Tell me briefly what's not adding up — attribution, identity, funnel data, whatever it is — and I'll tell you honestly whether it's worth an audit.