Why CTR Can Be the Most Misleading Metric in Digital Advertising

Why CTR Isn’t the Best Metric for Measuring Digital Ad Success

Click-through rate (CTR) has long been used as a primary measure of digital ad performance, but is it truly an accurate indicator of success? Steven Ohrnstein, Viant’s SVP of Platform Automation & Analytics, recently challenged the industry’s over-reliance on CTR, calling it one of the most misleading and overused metrics in marketing. Instead, he argues that advertisers should prioritize incrementality, customer lifetime value (LTV), and media mix effectiveness for a more accurate picture of performance.

In this post, we explore Steven’s post explaining why CTR can be misleading and outline better alternatives for measuring digital advertising success.

The Limitations of CTR in Digital Advertising

CTR measures the percentage of users who click on an ad after seeing it, but clicks don’t always equal genuine interest or conversions, according to Ohrnstein. Here’s why:

1. Mobile Ads Have Higher CTR—But Not Always for the Right Reasons

Looking at Viant DSP data from 5 billion impressions, Ohrnstein notes mobile smartphone ads yielded a 27% higher CTR than desktop/laptop ads. However, also according to Ohrnstein, this doesn’t necessarily mean mobile ads perform better—it could be due to “fat finger” accidental clicks from users navigating small screens.

2. Some of the Most Impactful Channels Have 0% CTR

Brand-building channels like Connected TV (CTV) and digital audio drive long-term awareness and influence consumer decisions—but they don’t generate clicks. Despite having a 0% CTR, notes Ohrnstein, these channels create demand that leads to future conversions.

3. Most Consumers Don’t Click Before Buying

Think about your own shopping behavior—how often do you pause, click an ad, and immediately purchase? The reality is (as seen in demand-side platform (DSP) reporting),less than 2% of transactions result directly from a click, according to Ohrnstein. Basing ad spend on CTR alone overlooks the majority of consumer decision-making behaviors.

What Advertisers Should Focus on Instead of CTR

1. Incrementality Testing: Did the Ad Actually Influence Behavior?

Incrementality measures whether an ad influenced a conversion or if it would have happened anyway. Advertisers can use Universal Pixels to track multiple actions (page views, add-to-cart, purchases) and measure true lift rather than just last-click attribution.

2. Revenue Impact & Customer Lifetime Value (LTV)

High CTR does not always mean high-quality customers. Are you acquiring valuable, repeat buyers or just paying for low-intent clicks? Evaluating customer LTV and purchase patterns can provide a clearer measure of an ad’s long-term success.

3. Media Mix Effectiveness: Are You Creating Demand or Just Capturing It?

Some channels, like search and retargeting, are designed to capture existing demand, while channels like CTV and digital audio help create demand. A balanced media mix strategy helps ensure that you’re not just optimizing for clicks but for business growth.

Final Thoughts: Move Beyond CTR for Smarter Advertising

While CTR has its place, relying on it too heavily can lead to misleading conclusions and inefficient ad spend. As Steven Ohrnstein highlights, marketers who optimize for clicks instead of business outcomes potentially leave money on the table. Instead, shifting focus to incrementality, LTV, and media mix effectiveness can help lead to stronger, data-driven marketing decisions that drive real growth.

For digital advertisers looking to maximize ROI and create sustainable demand, it’s time to move beyond CTR and focus on metrics that truly matter.