You Improved Every Part of Your Marketing. That's What Broke It.

Your Google Ads manager improved click-through rate by 15%. Your web developer increased form submissions by 40%. Your email platform shows open rates up 22%. Your CRM dashboards are all green.

Revenue is flat. Cost per acquisition went up.

Everyone did their job well. Every individual metric improved. And somehow the business is worse off than it was three months ago. This isn't bad luck. It's a predictable consequence of how most businesses approach marketing optimisation. And it has a name.

The Law Nobody Told You About

In 1975, British economist Charles Goodhart published a paper on monetary policy that contained a single observation now known as Goodhart's Law: "When a measure becomes a target, it ceases to be a good measure."

The original context was central banking. But the principle explains more about why marketing campaigns fail than any advertising textbook ever will.

Here's how it plays out. You give your Google Ads manager a target: improve CTR. They write more compelling headlines, tighten keyword match types, add more emotional hooks. CTR goes up. But the clicks you're now attracting aren't the same clicks you were attracting before. The broader, catchier ads pull in more browsers and fewer buyers. Your cost per lead rises even as your click rate improves.

You tell your web developer: get more form submissions. They reduce form fields from five to three. HubSpot's research across 40,000 customers found that reducing from four fields to three can increase submissions by nearly 50%. Submissions spike. But you removed the qualifying question that helped your sales team distinguish real prospects from tyre kickers. Lead volume goes up. Lead quality falls off a cliff. Your salespeople waste more hours per closed deal than ever before.

Each person optimised their piece. Each metric improved. And the overall system got worse.

This Has a Name in Systems Thinking

Manufacturing figured this out decades ago. Eli Goldratt's Theory of Constraints demonstrated that optimising any part of a system that isn't the bottleneck makes the whole system worse, not better. Speed up the assembly line before the painting station can handle the volume, and you just create a bigger pile of unpainted inventory.

Marketing works the same way.

Your marketing isn't a collection of independent parts. It's a system where each step feeds the next. Ads feed landing pages. Landing pages feed forms. Forms feed salespeople. Salespeople feed revenue. When you optimise one step without understanding its effect on the steps that follow, you create what systems thinkers call sub-optimisation: the illusion of improvement that makes the overall outcome worse.

As Tom Fishburne captured in his July 2026 Marketoonist cartoon: when we optimise for a number instead of our true goal, we risk whatever we were trying to improve in the first place. An optimisation algorithm, whether run by a human or a machine, is only as good as the metric it's designed to optimise. And the routes it finds can be technically correct yet damaging in the long run.

Three Ways This Quietly Destroys Your Marketing

1. The CTR Trap

Google Ads rewards high click-through rates with lower costs per click. So optimising for CTR seems rational. It is, if the clicks convert at the same rate.

They usually don't.

Broad, curiosity-driven headlines ("Discover Our Amazing Secret") generate higher CTR than specific, qualifying headlines ("Commercial Scaffolding Hire in Adelaide from $2,400/week"). But the first headline attracts everyone. The second attracts buyers. Smart Insights reports that the most common cause of high CTR paired with low conversions is attracting the wrong search intent: people who click out of curiosity, not purchase readiness.

The practitioner's trap: your Google Ads dashboard shows green arrows on CTR. Your bank account shows red.

2. The Form Field Paradox

The CRO community has spent a decade evangelising shorter forms. The data supports it, up to a point. HubSpot found that three-field forms convert best, and each additional field reduces conversions by roughly 4%.

But conversion rate is not the same as revenue.

A trades business we work with added a single qualifying question to their contact form: "What's the nature of your enquiry?" Options included emergency callout, quote request, and general question. Form submissions dropped 18%. But the team stopped spending 40% of their callback time on people who wanted free advice over the phone. Close rate on remaining leads nearly doubled. Revenue from the same ad spend increased.

The form "got worse" by every CRO metric. The business got better by every metric that matters.

3. The Speed-to-Lead Overcorrection

Research consistently shows that faster follow-up converts more leads. A study analysing 2.24 million sales leads found that contacting a prospect within five minutes makes them 21 times more likely to convert than waiting 30 minutes.

So businesses automate instant callbacks. The phone rings within 60 seconds of a form submission.

For some industries, this is brilliant. For others, it backfires. A professional services prospect who submitted a thoughtful enquiry at 2pm doesn't expect their phone to ring before they've closed the browser tab. The speed signals desperation, not attentiveness. Context determines whether speed helps or hurts: the optimal response time depends on the industry, the channel, the time of day, and how the lead was generated.

Optimising for speed-to-lead as a universal metric ignores the psychology of the person at the other end. We've written before about how your ads can be working perfectly while your follow-up process kills the sale. Speed is just one of the ways that happens.

Why Your Brain Falls for This Every Time

Daniel Kahneman's concept of WYSIATI ("What You See Is All There Is") explains why this trap is so persistent. When you see CTR improving on a dashboard, your brain constructs a coherent story: "Our ads are getting better." It doesn't spontaneously ask "What am I not seeing?" It doesn't wonder whether the new clicks are lower quality. It doesn't check whether form submission volume correlates with revenue.

The more coherent the story your metrics tell, the more confident you feel. But coherence does not equal validity.

Your dashboard shows you what improved. It cannot show you what degraded as a consequence. This is why your marketing dashboard can be technically accurate and still completely misleading. Each number is correct. The story they tell together is wrong.

Sam Tomlinson makes this point sharply in his audit framework: 99% of ad account audits fail because they obsess over tactical levers like CTR and Quality Score instead of strategic drivers. Google themselves have confirmed that Quality Score is a diagnostic tool, not an auction input. It's a lagging indicator. Yet entire agencies build their reporting around it. The audit celebrates the symptom while missing the disease.

The Metric Hierarchy Most Businesses Have Upside Down

Avinash Kaushik's KPI accountability framework organises metrics into three tiers. Most businesses live exclusively in the bottom one.

The sub-optimisation trap lives almost entirely in the Activity tier. Each activity metric improves. Nobody checks whether the improvements translate upward.

Kaushik's recommendation: pick one Success KPI per initiative, and make it an accountability metric, not an activity metric. Everything else is diagnostic. You track it for context. You don't celebrate it in isolation.

Les Binet and Peter Field's IPA effectiveness research across approximately 1,000 campaigns reaches a parallel conclusion at the strategic level. Marketing that optimises for short-term activation metrics (clicks, conversions, immediate ROAS) at the expense of long-term brand effects produces diminishing returns over time. The campaigns that drive the most profit allocate roughly 60% to long-term brand building and 40% to short-term activation. Most SMEs allocate close to 100% to activation and wonder why growth stalls.

This is sub-optimisation at the strategic level. Every quarter looks acceptable. Every year looks the same. We explored this tension in why your marketing works in quarters while your customers think in years.

What the Numbers Actually Look Like

Here's what two versions of the same marketing budget look like when you trace them through to revenue:

Fewer clicks. Fewer form fills. Fewer leads. Nearly double the revenue. The "optimised" version wins every metric your agency reports on. The "worse" version wins every metric that pays your bills.

This is why your marketing is a multiplication problem, not an addition problem. When one factor in the chain improves at the expense of another, the total can drop even though individual components look better. A 40% increase in leads multiplied by a 60% decrease in close rate is a net loss. The maths doesn't care that your dashboard is green.

What This Means for Your Business

Every time you set a target for a single marketing metric, you're creating an incentive to game it. Not deliberately. Not maliciously. But inevitably, because the person or algorithm optimising that metric will find the easiest path to improve the number, and that path almost never accounts for downstream effects.

Three things to do this week:

Charles Goodhart was talking about central banking in 1975. Half a century later, his observation is the single most important idea in marketing measurement that almost nobody applies.

Your marketing is a system. Optimise it like one.

Further Reading

• Smart KPIs: Accountability Over Outcomes Over Activity by Avinash Kaushik: The framework for distinguishing activity metrics from accountability metrics
• Theory of Constraints 102: The Illusion of Local Optima by Tiago Forte: How optimising individual components degrades system performance
• Optimizing for the Wrong Metrics by Tom Fishburne: A sharp visual take on Goodhart's Law in marketing
• The Long and the Short of It by Les Binet & Peter Field: IPA research on why short-term metric optimisation undermines long-term growth
• Goodhart's Law in Marketing: Balance Over Chasing Metrics: How metric targeting backfires in marketing strategy