Your customer acquisition cost is probably wrong. Not because your finance team made a calculation error, but because the denominator — the spend you're attributing to customer acquisition — almost certainly includes budget that isn't working, and excludes channels that are.
Here's the pattern we see in almost every audit.
The spend that doesn't show up
There's a category of acquisition cost that almost no company tracks properly: content production costs, team time spent on distribution, tools and infrastructure that support multiple channels.
When a company says "our CAC is £1,200," they usually mean: what we spent on paid ads, divided by customers acquired. They don't mean: what it actually cost us to acquire a customer across everything we invested.
The real number is usually 40–70% higher.
This matters because when you optimise against an incomplete CAC figure, you make systematically wrong tradeoff decisions. You pull budget from things that look expensive and don't account for what they were subsidising. You declare channels inefficient that are actually carrying more weight than they appear.
The channel misalignment problem
The second issue is more common and more expensive: budget concentrated in channels that aren't actually driving qualified pipeline.
What we typically find: one or two channels receive the majority of paid spend because they show attribution in the reporting. But the attribution is wrong. These channels are capturing credit for intent created elsewhere — usually organic content, brand awareness campaigns, or word of mouth that showed up as branded search.
When we reallocate budget to the actual high-signal channels and pull spend from the credit-capturing ones, CAC drops. Not because we found some new channel, but because we stopped misreading the existing data.
Why this happens at every company
Three structural reasons:
Marketing owns the reporting. The teams measuring channels are also the teams with budget at stake. This isn't bad intent — it's incentive structure. When a channel team owns the attribution model for their own channel, credit tends to flow toward them.
Tools optimise for what they can measure. Paid platforms report on what's trackable through their pixel. Organic content teams report on rankings and traffic. Nobody is looking at the combined picture of what actually preceded a closed deal.
CAC conversations happen at the wrong frequency. Most companies review CAC quarterly or annually. By the time misattribution is visible, months of misdirected spend have already happened. The fix is building a CAC review that runs continuously, not periodically.
How to diagnose your own CAC problem
Ask your team three questions:
- What is our current CAC by channel — fully loaded, including team time and tooling?
- What was our CAC by channel 12 months ago, and what changed?
- What channels do we not track cost against, and why?
The third question is usually the most revealing. The answer is almost always: we don't have a good way to attribute those costs. That's not a reason to stop looking — it's the reason to start.
What good CAC work actually looks like
A CAC audit isn't a one-time exercise. It's a process you build.
The companies that get this right have three things in place. A consistent definition of what counts as acquisition spend — agreed across finance, marketing, and growth. A regular cadence of closed/won analysis that goes deeper than last-touch attribution. And a quarterly reallocation review where budget decisions are made from the corrected picture, not the model.
None of this is technically complicated. Most of it is agreement and discipline. But it changes every downstream decision — what you build, where you hire, how you scale.
CAC problems are almost always attribution problems. Find the misattribution, and you'll usually find the spend to reallocate.
