The budget didn't get cut because it wasn't working. It got cut because nobody could prove it was

Most marketing budget cuts aren't a verdict on performance, instead they're a verdict on proof.

The investment was probably doing its job but when Finance sat down to find savings, nobody in the room could show what switching it off would cost.

Analytics shapes marketing's decisions, not the decisions made about marketing

Attribution, Lift testing and Marketing mix modelling (MMM) have real influence inside marketing teams. It shapes channel plans, flighting and how the budget gets split.

It has far less influence on the decisions made about those teams, like how much budget they get next year.

The reason is simple, the analytics sits too far from Finance. Finance either doesn't trust it, or doesn't know it exists.

So when the budget round comes, Finance works from what it already has easy access to e.g. last-click, sales on promotion, new product launches and ultimately whatever shows up in the weekly numbers.

This isn't a niche problem, the CMO Survey found 64% of marketers name proving marketing's impact on financial outcomes as their top challenge, a figure that has been climbing for years (CMSWire).

And you'll know the question that follows. As The Drum put it: "If marketing works, why can't you prove it properly?"

When marketing's contribution isn't in the P&L, it looks like a cost

Look at how most P&Ls treat marketing - it sits there as a cost line with the incremental impact rarely tracked alongside it.

Growth gets credited somewhere else: it goes to the promotion that ran that month, to the launch of the latest NPD or to the sales tracked via last-click or another digital platform before purchase.

In a tough year, that makes marketing one of the easiest lines to switch off. A clean saving, with no visible downside.

This isn't a future problem as budgets are already under pressure. Gartner's CMO Spend Survey put marketing at 7.7% of company revenue in 2025, down from 9.5% three years earlier (Gartner, via CMSWire).

When costs are under scrutiny, pushing harder for more budget without proof is not going to be successful. Gartner predicts over 40% of CMOs who push for bigger budgets will lose influence with the C-suite, because they can't show clear ROI (CX Today).

Finance are only looking for information that they trust and that helps them make informed decisions.

The same blind spot drives bad decisions the other way

When the business is behind target, the question flips.

How much do we need to put into marketing to hit the number? Will another £2m get us there? We need 10% growth, so should we add 10% to the budget?

Each of those misses something.

Diminishing returns: The next £2m potentially won't work as hard as the first. Media inflation: The same budget buys less each year. Scale of contribution: If marketing drives 10 to 20% of overall performance, a 10% budget increase delivers far less than 10% growth. Spending 'last minute' can lead to a lower ROI: you end up buying poorer inventory, running creative that isn't ready and making weaker decisions.

• Diminishing returns: The next £2m potentially won't work as hard as the first.
• Media inflation: The same budget buys less each year.
• Scale of contribution: If marketing drives 10 to 20% of overall performance, a 10% budget increase delivers far less than 10% growth.
• Spending 'last minute' can lead to a lower ROI: you end up buying poorer inventory, running creative that isn't ready and making weaker decisions.

ROI targets have the same flaw in that a business sets a target ROI, then holds every spend level to it.

ROI isn't fixed and it changes as spend levels change. The useful question is what's the best ROI you can achieve at a given level of spend and what does this translate to in terms of net profit.

Comparing ROI across different budgets gives a misleading read and leads to poor decision making, whether you're cutting or adding budget.

Better reporting won't fix this, getting Finance into the model will

Most teams try to solve the trust problem with a better deck for Finance, a cleaner dashboard, a tighter ROI slide etc. This is not the short-cut that is going to work.

These approaches keep Finance on the outside, judging outputs they had no part in building.

What Finance needs is visibility into how the model works, they need to know the assumptions, what's in, what's out and importantly how uncertainty is handled.

This shared interpretation and understanding helps build trust whilst careful orchestration regarding what Finance can see creates doubts.

Three things change when Finance is 'on the inside'.

First, the model has to cover the full commercial picture, not just the media but include promotions, pricing, CRM, distribution and launches too. Otherwise Finance is looking at a partial view skewed towards the media, and they know it. This full commercial view is where econometrics earns its place in the Finance conversation.

Second, it has to prove itself. MMM is a model, it aggregates data and uses statistics to quantify the impact. Lift testing / test-and-control show that when a lever gets pulled, the outcome matches the forecast. That turns "the model says" into "we tested it and it held". This is evidence that the model is working.

Third, it has to look forward. It should show the full impact of a cut in year one, year two and year three on the P&L. It must not just show the impact of saving in the present.

A cut can be the right call, just make the decision with the full picture

This isn't an argument against ever cutting marketing, sometimes a short-term saving is the right decision.

But a cut that looks free in year one can cost far more in years two and three. Finance should see that before deciding, not after.

Once Finance trusts the model, the conversation changes. Marketing stops only being asked how it will deploy the budget. It starts being asked what the right budget is to hit the target.

That's a different seat at the table.

What to do before your next budget round

Build the model with Finance in the room and share the assumptions and the uncertainty, not just the headline number. You are on the same team. Answer "what does another £2m deliver?" with a model, not a guess. Show outcomes at different spend levels, diminishing returns included, before anyone proposes a round number. Ensure you have a budget setting process that plans ahead rather than reacts. Prove the forecast before you ask Finance to trust it. Use lift tests and test-and-control to validate what the model predicts.

• Build the model with Finance in the room and share the assumptions and the uncertainty, not just the headline number. You are on the same team.
• Answer "what does another £2m deliver?" with a model, not a guess. Show outcomes at different spend levels, diminishing returns included, before anyone proposes a round number. Ensure you have a budget setting process that plans ahead rather than reacts.
• Prove the forecast before you ask Finance to trust it. Use lift tests and test-and-control to validate what the model predicts.

Summary

Budgets rarely get cut because the spend failed, they get cut because the value never reached the people making the decision.

Finance doesn't trust what it can't see. Marketing's contribution rarely shows up in the P&L. ROI moves with spend, so fixed targets mislead. Cuts carry costs in years two and three that nobody models.

• Finance doesn't trust what it can't see.
• Marketing's contribution rarely shows up in the P&L.
• ROI moves with spend, so fixed targets mislead.
• Cuts carry costs in years two and three that nobody models.

So stop showing Finance your ROI and start showing them your contribution to the P&L.

ROI is a marketing number. Profit contribution is a Finance number and it sits on their statement, next to every other lever they're weighing up.

Show that, and cutting marketing stops being a free saving. It becomes a trade-off Finance has to own.

When did your Finance team last see how your model works, not just what it says?

Sources

Who's Really Accountable When Marketing Misses Its Revenue Number? CMSWire Why marketing loses budget, and how to stop being the easy cut in 2026, The Drum Gartner 2025 CMO Spend Survey, Gartner Marketing ROI in the Era of Flat Budgets and Rising Expectations, CX Today

• Who's Really Accountable When Marketing Misses Its Revenue Number? CMSWire
• Why marketing loses budget, and how to stop being the easy cut in 2026, The Drum
• Gartner 2025 CMO Spend Survey, Gartner
• Marketing ROI in the Era of Flat Budgets and Rising Expectations, CX Today