Yet, every marketer operates on applied theory, whether consciously or not. Deciding to prioritise loyalty over reach, put more budget into performance than brand building, or define a particular group as the "core customer" often rests on assumptions about how marketing works.

The problem is not theory. It is theory that has become convention without being tested. An idea heard from a former manager, agency, conference speaker, or technology vendor can acquire the status of fact simply because it has been repeated often enough. This can be an expensive way to make decisions.

There is evidence that marketers are struggling to connect activity with outcomes. The 2025 CMO Survey found that 64% of marketing leaders find it challenging to demonstrate the financial impact of marketing actions, while 51.8% struggle to focus data and analytics on the marketing problems that matter most.

Similarly, Nielsen's 2025 Annual Marketing Report found that only 32% of global marketers measure traditional and digital media spending holistically.

More data, then, can give established assumptions more dashboards through which to present themselves, but it does not necessarily produce better decisions.

This becomes more significant as measurement itself becomes harder. Fragmented platforms and changing consumer journeys make it increasingly difficult to establish what actually caused an outcome. Platform-reported attribution can tell us what happened around a campaign, but it cannot always tell us what would have happened without it.

This is where methods such as marketing mix modelling, incrementality testing, geo-lift experiments, and matched-market design become commercially relevant. They require marketers to think in terms of causality rather than simply correlation.

AI adds another layer. IAB SA reports that 78% of South African marketers were already using AI tools such as ChatGPT and InVideo in 2025. However, even as AI makes research, analysis and content production faster, it also makes it easier to reproduce an assumption at scale. The ability to question an output becomes as important as the ability to generate one.

This calls for marketing education that does more than teach students how to apply the latest tools. Marketers need a grounding in theory, research, and evidence, but they also need opportunities to test these foundations against practical problems.

They should learn to ask where an idea comes from, what evidence supports it, how it can be tested, and what would change their minds.

For new entrants into the industry, this relationship between theory and practice needs to be built into their tertiary learning experience rather than added through occasional on-the-job exposure.

Live briefs, simulated agency environments, research and work integrated learning combine to place theory under the pressure of real constraints, while academic assessment enforces the discipline that is needed to reflect on what worked, what did not and why.

The objective is not to produce marketers who can recite theory. It is to develop professionals who can use theory intelligently to recognise when conventional wisdom is unsupported, and then adapt their thinking if the evidence points elsewhere.

The strongest marketers of the future won't necessarily be those who use the most platforms or can produce the fastest output. They will be those who understand the thinking behind their decisions and can distinguish evidence from convention. Most importantly, they will know when marketing needs more evidence and less certainty.

For more information, visit www.aaaschool.ac.za. You can also follow The AAA School of Advertising on Facebook, X, or on Instagram.

*Image courtesy of contributor