Written by Sophie Cameron

Marketers have more tools and platforms than ever to reach audiences. From social media and search to email and influencer partnerships, there’s no shortage of ways to connect with potential customers. Yet this abundance of choice leads to a critical question: Is your marketing actually working? 

In simple terms, incrementality is about measuring the actual impact of your marketing efforts. Advertisers invest across many different channels with the intention of driving results. The challenge is figuring out whether those results directly link to marketing activity or whether they would have happened anyway without the spend. 

For instance, if a customer was already planning to purchase your product, seeing an ad right before checkout may not have been why they clicked “buy.” On the other hand, if the ad nudged them to make a decision they weren’t sure about, that action can be attributed to marketing’s incremental impact. Incrementality testing helps draw the line between these two outcomes, while measuring incrementality is the difference between knowing your marketing influenced a customer’s decision versus simply being present when the customer was already going to act. 

The Advantages of Measuring Incrementality 

The value of understanding incrementality extends far beyond curiosity. For marketers working with limited budgets, measuring actual impact is essential for long-term success. 

Some of the key benefits include: 

Smarter budget allocation: By identifying which campaigns are actually moving the needle, you can stop pouring money into channels that only appear to perform well but are not producing incremental results, ensuring every penny invested in media works as hard as possible. 

Deeper customer insights: Incrementality reveals how your audience interacts with marketing messages across different platforms. For example, you may discover that paid search drives incremental conversions among first-time customers, while social media primarily reinforces the loyalty of returning buyers. These insights can help refine both creative and channel strategy.

Stronger accountability: Executives and stakeholders want more than vanity marketing metrics like clicks and impressions. Incrementality allows marketing teams to present concrete data that proves real impact. This data builds confidence in marketing investments and strengthens the case for additional resources. 

How Do You Measure Incrementality? 

While the concept is straightforward, proving incrementality requires deliberate testing and analysis. There are a few core methods that marketers can use to measure the actual impact of their efforts. 

Geo Testing: This approach involves running a campaign in a specific geographic region while withholding the same campaign in a comparable region. For example, you might launch paid social ads in Toronto but not Vancouver. By comparing sales, sign-ups, or engagement between the two cities, you can see whether the campaign drove incremental results or similar outcomes would have happened without the spend. Geo testing is beneficial for large-scale campaigns with clear regional segmentation. 

Holdout Experiments: Another common technique is the holdout test, which involves splitting your audience into two groups. One group is exposed to the campaign, while the other group, the holdout, does not see it. By comparing performance between the two groups, you can identify whether your marketing strategy had a meaningful impact. For example, if the test group purchases at a significantly higher rate than the holdout group, you can confidently attribute that lift to marketing activity. Holdout experiments are a gold standard for proving causality because they directly isolate the influence of marketing exposure. 

Incrementality Modelling and Attribution: Marketers often use advanced modelling techniques for more complex, multi-channel campaigns. Incrementality modelling uses statistical analysis to estimate the actual contribution of each channel while accounting for overlapping exposures. When combined with marketing attribution tools, this helps paint a more complete picture of how different channels work together to drive results. While these models are not foolproof, they become more powerful when validated against real-world tests like geo or holdout experiments. 

Why Incrementality Matters More Than Ever 

The digital marketing ecosystem is becoming increasingly complex. Consumers are exposed to multiple touchpoints before making a purchase decision, and privacy regulations limit the amount of individual-level data available to advertisers. As a result, traditional marketing attribution methods that rely heavily on tracking clicks and conversions are no longer enough to prove effectiveness.

Incrementality provides a more reliable framework because it focuses on outcomes that would not have happened without marketing, shifting the conversation from measuring activity to measuring actual business impact. For marketing teams under pressure to justify spend, this approach is invaluable. 

Moreover, incrementality helps organisations stay agile. By running regular tests and continuously analysing incremental lift, brands can make smarter decisions about where to invest, which campaigns to scale, and which to sunset. It transforms marketing from a cost centre into a proven driver of growth.

At Tug, we’ve developed Real Impact, a tool part of our suite of proprietary martech ‘Tug Tools’. 

Real Impact is an advanced causal modelling tool that ingests multi-channel campaign data in near real-time, providing a statistically robust impact score of one data set against another that can be used in place of attribution. The tool can provide monetary value for clients to understand the impact of their campaigns in cases where traditional marketing attribution methods cannot display the full picture, and performance metrics consist of disconnected datasets. 

Speak to our Paid Media team to find out more.