Because it genuinely is — acquisition costs have risen roughly 40–60% since 2023, ad platforms keep getting pricier, and plenty of companies now spend around £2 to buy £1 of new revenue. The trap is treating that as a media problem. Usually it isn't. A rising cost-per-customer is a symptom, and the cause tends to be a level up: a proposition that doesn't stand out, the wrong audience, a weak message, or a funnel that leaks what you paid for. CAC only means something next to lifetime value and payback — a healthy business earns back at least £3 for every £1 spent, and recovers the cost inside a year or so. If that ratio's slipping, more budget won't fix it.
We find where the cost is really coming from — proposition, audience, message or funnel — by reading the behaviour, not just the dashboards. Then we sharpen the thing that's actually broken and prove the fix with small experiments before you pour more into paid.