In an era where every online activity is measured—from views to clicks to leads generated—digital marketing metrics have become the compass for companies and marketers.
But what happens when those same metrics, instead of guiding, begin to mislead?
This is where Goodhart’s Law comes into play, one of the most cited rules in economics and increasingly relevant today in the digital world as well. Understanding it is essential to build data-driven marketing strategies that truly deliver value and don’t stop at so-called “vanity metrics.”
Origins of Goodhart’s Law
Goodhart’s Law is named after British economist Charles Goodhart, who in 1975, in a paper for the Bank of England, wrote:
“When a measure becomes a target, it ceases to be a good measure.”
(“When a measurement becomes a target, it ceases to be a good measurement.”)
The context was that of economic policy: the indicators used to monitor economic performance worked well as analytical tools, but the moment they became “official targets” to be achieved, markets and banks changed their behavior to achieve them, thus rendering them useless as reliable measures.
In short, if a number becomes the target, people find ways to manipulate it, even at the expense of the real value it should represent.
Everyday Examples
- School: If the measure is the grade, students study to pass the exam, not to actually learn.
- Business: If the KPI is the number of emails sent, the marketing team will increase emails, even if they’re irrelevant to customers.
- Healthcare: If the goal is to reduce emergency room wait times, there’s a risk of discharging patients too early just to lower the average.
Goodhart’s Law in the Age of Social Media
With Facebook, Instagram, TikTok, and other platforms, the law is clearly evident.
Performance indicators easily become targets for optimization:
- Likes and reactions: If only likes count, superficial content, memes, or clickbait headlines are produced.
- Followers: If the goal is to increase the number of followers, artificial practices such as buying followers or “follow for follow” exchanges proliferate.
- Views: If the indicator is the number of views, short, sensational videos are promoted, even if they don’t educate or strengthen the brand.
In all these cases, the metric grows, but the real value (trust, authentic engagement, sales) declines.
Implications for Digital Marketing
In digital marketing, Goodhart’s Law warns against a common mistake: mistaking vanity metrics for real results.
- A brand can boast of having 100,000 followers, but if no one interacts or purchases, that metric is empty.
- A campaign may generate a high CTR, but if the product isn’t purchased, the “success” is only apparent.
- An eCommerce business can increase orders with aggressive promotions, but if margins drop and customers don’t return, business deteriorates.
How to act accordingly
If metrics risk betraying us, then the key is to establish measurement systems and objectives that remain meaningful.
1. Choose KPIs that reflect true value
Don’t stop at what’s easiest to measure.
Social: It’s better to measure the interaction rate than the likes.
eCommerce: Average margin and retention matter more than the raw number of orders.
Always ask yourself: does this metric truly represent valuable behavior for the customer and the company?
2. Set long-term goals
Incentives drive behavior.
Instead of focusing solely on growing followers, work on objectives like “increase qualified newsletter subscribers” or “increase repeat customers.”
This way, you create content and strategies that strengthen your business, not just the numbers.
3. Combine numbers and quality
Quantitative data must be supported by qualitative indicators.
eCommerce example: conversion rate + customer reviews.
Social example: reach + quality of conversations in comments.
This way, you distinguish apparent quantity from real quality.
4. Beware of internal incentives
Goodhart’s Law also applies to organizations.
If you reward your marketing team only for leads generated, you’ll find a CRM full of useless contacts.
If you only look at cost per click, you risk attracting irrelevant traffic.
Balanced evaluation systems are better: not just “leads generated,” but “qualified leads that become customers.”
5. Use a “north star metric”
Successful companies choose a guiding metric that captures true customer value:
- Airbnb: nights booked.
- Facebook (initially): daily active users.
- eCommerce: percentage of customers who purchase at least twice in 90 days.
The north star metric acts as a compass and prevents you from getting lost in vanity metrics.
6. Adapt metrics to the company’s lifecycle
Metrics must mature along with the business.
Initially, growing the user base is important.
Later, retention, LTV (Customer Lifetime Value), and customer satisfaction become crucial.
Always measuring in the same way leads to distorted views.
7. Build balanced metrics systems
The key is not to eliminate metrics, but to build a balanced system.
For each indicator, combine one that offsets its limitations:
- Volume ↔ Quality: combine the number of leads with the percentage of qualified leads.
- Short Term ↔ Long Term: combine immediate sales with retention or customer lifetime value.
- Internal ↔ Customer: combine customer care response times with perceived customer satisfaction (NPS, reviews).
A structured approach is the Balanced Scorecard, developed by Kaplan and Norton in the 1990s: a methodology that encourages integrated performance measurement, balancing financial, operational, learning, and, above all, customer impact perspectives.
In practice, this means combining lagging indicators (those that measure results that have already occurred, such as revenue or sales) with leading indicators (those that predict future performance, such as the adoption rate of a new feature or the number of customers who sign up for a demo).
This reduces the distorting effects described by Goodhart’s Law and maintains a more realistic picture, geared towards sustainable growth.
Conclusion
Goodhart’s Law reminds us that metrics are tools, not blind goals. In digital marketing, where we’re inundated with dashboards and numbers, it’s easy to fall into the trap of “vanity metrics.”
But truly growing means measuring what matters: authentic relationships, satisfied customers, concrete business results.
In other words: Don’t optimize what’s easiest to measure, but what generates real value.
 | Growth is not measured in likes: find out what really matters.Lean on a HubSpot partner like Kiosk to help you build a Marketing and sales system based on actionable data, intelligent automation, and measurable growth. |
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Growth is not measured in likes: find out what matters Really.Trust a HubSpot partner like Kiosk, which helps you build a marketing and sales system based on truly actionable data, intelligent automation, and measurable growth.
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