In 2025, economic uncertainty is more than a backdrop, it's reshaping how brands plan, spend, and grow. For marketers, one of the clearest emerging challenges is the ability to acquire new customers profitably to fuel growth. Whether due to rising media costs, declining consumer confidence, or tightening budgets, many brands are seeing slower growth at the top of the funnel, making lower-funnel efficiency more important (and more fragile) than ever.
If new customer acquisition slows, it may seem logical to lean harder on the lower funnel. But here’s the catch: Many marketers are unknowingly overspending on non-incremental lower-funnel conversions, driven by automated media products that favor highly engaged new customers or existing customers — tactics that are often great for capturing existing demand, but not for growing it.
In this environment, brands need to do more than optimize. They need to measure what’s actually driving incremental results and retool their lower-funnel strategies accordingly.
The New Challenge: When Upper Funnel Shrinks, Pressure Builds Below
During periods of growth, marketers can afford a little inefficiency. When customer acquisition is strong, the lower funnel benefits from a steady inflow of new traffic to retarget, convert, and monetize. But when that top-of-funnel flow slows — due to macroeconomic pressures, weaker seasonal performance, or competitive shifts — the lower funnel gets starved and performance starts to degrade.
To make matters more complicated, platform automation doesn't always know the difference. Tools like Google’s Performance Max (PMAX) or Meta’s Advantage+ Shopping Campaigns (ASC) are designed to generate conversions. But without clear constraints, they often gravitate toward existing customers, retargeted audiences, and branded queries. The result? Great-looking ROAS, but limited incremental value.
Why Lower Funnel ROAS Can Be Misleading
Lower-funnel metrics like click-through rate and attributed ROAS often look strong because they capture high-intent customers who were likely to convert anyway. But that doesn’t mean those conversions were caused by the ad.
Measured data shows that channels like brand search or dynamic retargeting frequently overstate their business impact by up to 60% when evaluated through last-click attribution. That might be fine in a world with endless acquisition, but when growth slows, it leads to dangerous inefficiency.
If your lower funnel is filled with media that’s primarily monetizing existing demand, you’re not fueling new growth, you’re just recycling your existing customer base. That’s not a strategy, it’s a plateau.
The Fix: Full-Funnel Incrementality and Smart Lower-Funnel Tuning
So what can marketers do? First, they need to stop optimizing based on correlation and start measuring true incrementality. That means running controlled geo or audience tests to isolate the causal impact of lower-funnel campaigns and revealing whether those retargeting or branded search tactics are really driving new business or just intercepting it.
Second, marketers need to tune their automation to prioritize incremental new customer growth. For platforms like PMAX and ASC, that includes:
- New customer acquisition (NCA) bidding: Set campaign objectives to focus on first-time buyers only.
- Customer caps or exclusions: Suppress existing customers from certain campaigns to force platforms to prospect.
- Segmentation: Break out branded vs. non-branded queries and prospecting vs. retargeting audiences to apply stricter controls.
When marketers get disciplined about how lower-funnel automation is used, they gain control over performance and protect profitability, even in lean times.
The Bigger Picture: Don’t Over-Invest in the Familiar
In times of economic pressure, it’s natural to retreat to what’s familiar. Lower-funnel tactics are easy to justify. They often come with strong attribution numbers and short payback windows. But if they aren’t driving incremental growth, they’re not protecting your business and they’re just creating the illusion of efficiency.
This is why incrementality matters more now than ever. It's the only way to understand what’s actually working across your entire funnel. And it’s the only way to make investment decisions you can trust, especially when new customer acquisition gets harder and every dollar counts.
Final Thought
If new customer growth is cooling off, the worst thing you can do is double down on tactics that just look good on paper. To navigate this moment, marketers need clarity, not comfort, and a commitment to measuring what really matters.
Your lower funnel won’t save you unless it’s incremental. Now’s the time to find out.
To learn more about how incrementality super-charge your brand strategy, check out The Essential Incrementality Playbook for Marketers — and get in touch with a Measured expert today.