The attribution iceberg: Why you're optimising for convenience, not contribution

To truly understand advertising effectiveness, marketers need to look beyond the surface to reveal hidden dangers and opportunities.  

Last-click attribution only reveals the final interaction before a conversion, like the tip of an iceberg. What lies beneath the surface is a vast, complex ecosystem of touchpoints, all of which contribute to the customer journey. Ignoring these touchpoints distorts performance insights and ultimately leads to misallocated budgets.  

Last-click attribution, therefore, creates a skewed perspective, favouring certain channels while neglecting others. As a result, marketing performance will be affected due to: 

• Bottom-funnel channels get all the credit, like paid search and retargeting 

• Undervaluing upper-funnel influence, such as display, video, and CTV 

• Reinforcing walled garden dominance - with Google, Meta and Amazon ads slated to be generating over 60% of global digital advertising revenue. 

The hidden costs of last-click attribution  

It’s a little-known fact that that last click attribution can contribute to hidden costs. For example:  

1. Starving brand growth  

Last-click attribution disproportionately rewards performance tactics while ignoring the upper-funnel strategies that drive long-term success. Think about the awareness-building power of display or video ads - efforts that may not lead to an immediate click but plant the seed for future conversions. This means that campaigns that fuel interest and consideration are being starved of budget - simply because they didn’t deliver the final click. 

​2. Bias toward walled gardens  

Platforms like Meta and Google dominate last-click reports because they “own” the final click, even when other channels have laid the groundwork. This creates a problematic feedback loop: budgets increasingly favour the dominant players, making it harder for other channels to prove their value or compete. 

3. Fake precision, real blind spots  

Last-click attribution may feel precise, but it paints an incomplete picture. The below chart illustrates an example of a multi-touchpoint path to purchase today. By using only last-click attribution, marketers may invest in tactics that may not actually move the needle. 

What marketers can do instead   

Given the clear limitations of last-click strategies, what alternatives can marketers adopt? Here are some effective, and more holistic strategies:  

1. Adopt multi-touch attribution (MTA) 

• Instead of assigning all credit to the final click, MTA distributes fractional credit across all touchpoints. It helps marketers see how different channels (such as display, social, video, and CTV) work together to drive conversions. It enables more informed budget allocations and effective optimisation. 

2. Use incrementality testing 

• Incrementality helps answer the question: “What would have happened if I hadn’t run this campaign?” By comparing exposed vs. unexposed groups, incrementality testing isolates true campaign impact beyond ‘vanity metrics’ like clicks or impressions. It’s a powerful way to identify which efforts are genuinely driving conversions.  

3. Balance performance with brand building  

• By pairing last-click attribution data with brand lift studies and long-term sales impact analysis, marketers can make better strategic decisions that support both immediate goals and sustained success.

By embracing a more comprehensive approach to measurement, marketers can accurately credit all contributors - media vendors, publishers, and ad tech partners; optimise campaigns for true incremental growth; and reduce dependence on walled gardens and build more diversified media strategies. 

If you’re only measuring the tip of the iceberg, you’re making critical decisions with incomplete information. It’s time to dive deeper, uncover the full picture, and reevaluate what drives marketing success.  

This article is sponsored by Quancast.