Stalled growth, rising pressure: why performance marketing is failing your brand, and how to regain control
Tom Elder
Tom Elder is a Managing Partner at Open Partners, bringing 16 years' experience in digital-first strategy, planning, and execution.
For the past decade, performance marketing has been the safe bet. It promised results that were both measurable and immediate. Boards could see return on investment down to the last click, and marketing teams could justify every pound spent. But for many brands, that comfort blanket is gone. Growth is slowing down, despite consistent – and even increased – budgets. Diminishing returns is the new reality.
If this sounds familiar, you’re not alone. It’s what thousands of advertisers are facing. Below, we dive into the reason behind slowing growth in performance marketing, highlighting what brands can do to turn things around and regain control of performance outcomes.
When performance marketing thrived on big budgets and tight control
There was a time when brands truly controlled their paid campaigns. We chose the keywords. We wrote the copy. We set the bids. We tweaked, refined and optimised until our strategies outperformed the competition. In pay-per-click (PPC), Google was king, but it was still our chessboard. We were smarter than the machines and we made them work for us.
Back then, pouring more budget into PPC made sense. More spend meant more clicks. More clicks meant more sales. Results were predictable, and proof of marketing’s value was easy to demonstrate to shareholders.
Now, the algorithm calls the shots
Times have changed. The digital landscape is now defined by AI-driven automation. Google’s acquisition of DeepMind in 2014 was the start of a new era. Its message to advertisers: “Leave it to us.” Campaigns once fine-tuned by human skill are now optimised inside a black box. Performance Max, Demand Gen, Meta Advantage+ – these products are built AI-first, invariably taking control away from marketers. In this space, those who train the algorithms the best (and the fastest) will be the winners.
The rise of AI + legacy paid media strategies = diminishing returns
Advertising is more scalable, personal, and powerful than ever, so why are brands seeing diminishing returns? It boils down to brands clinging to legacy performance strategies – throwing money at campaigns that are not fit-for-purpose in 2025, using a handful of creative assets that are unengaging and impersonal.
Using these tactics, performance marketing outcomes will continue to plateau. In a tougher economy, where every penny must prove its worth, this is unsustainable for any brand.
Success in performance marketing is now dictated by leveraging AI automation – training algorithms better and faster than anyone else. AI works best when it has more data to train on, and more creative assets to test with. Simply handing over money and waiting for results will put your brand at a major disadvantage as faster competitors feed the machine what it’s asking for.
The truth is, we’re no longer controlling Google’s AI – we’re training it. Those who train it best win. Those who don’t fall behind.
Regaining control – here’s what to do
Feed and train the beast
The fundamentals of marketing haven’t changed: humans set the vision, machines execute at speed. What’s changed is how we direct those machines. Success now depends on:
Better product data: rich, accurate feeds that tell the AI exactly what you sell and why it matters.
Better customer data: first-party insights to inform targeting beyond what your competitors provide.
Better business data: feeding full-funnel performance metrics back into the platforms to help algorithms optimise for real commercial outcomes.
When you train Google’s AI (and Meta’s too) better than anyone else, you win on their terms.
Combine human creativity with AI scalability + sustainability
AI can optimise at scale, but it can’t create meaning. That’s still a uniquely human skill. To thrive, brands must combine:
Human creativity: producing standout assets that capture attention and communicate value. This includes User Generated Content (UCG).
AI execution: delivering those assets at speed, scale and efficiency. This means creating multiple variations for algorithms to test and identify winners and losers.
Financial sustainability: utilising AI to drive efficiencies and reduce costs to ensure the approach is sustainable.
Why? Because in the world of AI advertising, creative assets are the biggest ROI lever, and the algorithm is hungry for more, more, more to test and optimise at scale.
The new performance marketing mandate
Performance marketing isn’t dead, but the old way of doing it is. To regain control:
Stop relying on legacy “set and forget” tactics.
Start training algorithms with better, richer, brand-owned data.
Combine human creativity with machine optimisation to keep costs sustainable and results scalable.
We’ve entered the era of feeding and training the machine. Those who adapt will accelerate. Those who don’t will be left wondering why they’re still spending more to get less.
At Open Partners, we’re experts at training the algorithms at speed and scale. We call ourselves ‘The Agency of Next’ because we think ahead so our clients don’t have to. If your brand is in need of a strategic performance marketing partner that focuses on material outcomes and growth, contact us below.
