Every boardroom conversation about marketing eventually circles back to the same question: What are we getting for the money? Media buying sits at the heart of that tension. It is where strategy becomes spend, and where spend must become measurable return.
In an environment where UK adspend reached £47.8bn in 2026, the pressure to demonstrate ROI has never been greater. Finance directors are scrutinising every line of the budget, and marketing leaders are under pressure to prove that investment drives growth, not just impressions.
This third article in our series turns to the practical side: how organisations can make sure their media buying delivers tangible return on investment.
Step 1: Start with Strategy
It sounds obvious, but too many campaigns fail because buying starts without clear objectives. Before the first pound is committed, brands need alignment on business goals (growth, retention, awareness, market share), audiences (who you’re targeting and why), and metrics (what success looks like: sales, leads, brand lift).
Without this, even the sharpest negotiation or slickest DSP setup can’t deliver ROI.
Consider ITV’s pivot to ITVX. Buyers who treated “TV” as a single homogeneous channel missed the opportunity to reach younger audiences shifting to digital. Those who anchored their strategy to audience behaviour, not tradition, bought BVOD inventory and captured ROI that others ignored.
Step 2: Leverage First-Party Data
With continued emphasis on privacy, first-party data has become the most valuable currency in media buying. Retail media networks are leading the way.
Tesco’s Clubcard platform, for example, reaches approximately 80% of UK households. Buying through Tesco Media & Insight isn’t just about impressions. It’s about purchasing access to verified shoppers and measuring actual sales uplift. For FMCG brands, this is ROI in its purest form: money in, sales out, with no guesswork in between.
For SMEs, the same principle applies at a smaller scale. Even modest CRM data can be activated through platforms that allow lookalike modelling or clean-room integrations. The brands that win will be those that treat data as an investment, not a by-product.
Step 3: Make Smart Channel Choices
The future of ROI-driven media buying isn’t about spreading thinly across every channel, but choosing the right mix for the right objectives.
CTV/BVOD is essential for incremental reach, especially among 16-34s who are under-represented in linear TV. Ad-funded SVOD now reaches 36% of this demographic weekly.
Programmatic DOOH offers cost-efficient reach with measurable footfall and sales impact. Boots’ weather-triggered campaigns are a case in point, driving seasonal product sales with precision. Retail media grew 23% in 2024, and links ad spend directly to purchase data, offering closed-loop measurement. Search and online display remain critical for capturing intent, with search accounting for 47% of digital ad spend.
The smart buyer doesn’t ask, “What’s cheapest?” but “Which channel advances my specific goal most efficiently?”
Step 4: Negotiate and Measure Relentlessly
ROI isn’t just about where you buy. It’s about how you buy. Strong buyers secure value through volume deals where appropriate, share-of-voice commitments in premium environments, and supply-path optimisation in programmatic to reduce hidden fees.
Measurement must go hand in hand. That means triangulating econometrics (MMM) to prove long-term contribution, incrementality testing to isolate channel impact, and platform lift studies to validate performance.
Thinkbox’s Profit Ability 2 study provides compelling evidence: advertising has an average short-term profit ROI of £1.87 per pound invested, which increases to £4.11 when sustained effects (up to 24 months) are included. Crucially, 58% of advertising’s total profit generation happens after the first 13 weeks, demonstrating the case for consistency and patience in measurement.
The study, which analysed £1.8 billion of media spend across 141 brands, found that TV advertising accounts for 54.7% of total advertising-generated profit, with an average full profit ROI of £5.61 per pound spent. But every major media channel contributes to profit. The key is measuring holistically, not in silos.
Step 5: Optimise Continuously
ROI isn’t won at the start of a campaign; it’s earned through constant optimisation.
- Weekly: rotate creative, monitor frequency caps, adjust bids, and prune wasteful placements.
- Monthly: rebalance the budget towards channels showing marginal gains.
- Quarterly: review ROI holistically, not just by channel, to ensure investment is driving growth.
The buyers who thrive aren’t those who “set and forget,” but those who see media as a living investment portfolio that needs constant rebalancing.
The SME Perspective
For SMEs, the stakes are higher. A wasted campaign doesn’t dent a £100m budget. It can drain the year’s marketing resources. That’s why ROI-driven buying is especially critical for smaller organisations. The smartest play is often to anchor in one high-intent channel (like search or retail media) and complement it with one upper-funnel driver (such as BVOD or programmatic DOOH).
Boots may run national-scale campaigns, but the principle scales down: targeted, dynamic buying that ties spend to measurable outcomes works whether you’re a multinational retailer or a regional brand.
The common pitfall for SMEs? Poor measurement hygiene. Too many run campaigns without proper tagging, clear KPIs, or any plan to track incrementality. ROI begins with discipline, not spending.
Building a Checklist for ROI
To ensure media buying delivers returns, organisations should challenge themselves against these questions:
- Are objectives and KPIs defined and agreed before campaigns launch?
- Is first-party data activated where possible?
- Are channels selected based on goals, not habit or legacy?
- Has negotiation reduced hidden fees and improved value?
- Is the measurement holistic, covering both the short- and long-term?
- Is optimisation embedded in weekly and monthly workflows?
If the answer to any of these is “no,” ROI is at risk.
Frequently Asked Questions
How long does it take to see ROI from media buying?
It depends on your objectives and channels. Search and retail media can show results within days or weeks. Brand-building through TV or DOOH takes longer to measure properly. Thinkbox’s research shows that 58% of advertising profits come after the first 13 weeks. Patience and consistent measurement are essential.
What’s a good ROI benchmark for media buying?
Benchmarks vary significantly by sector and channel. Thinkbox’s Profit Ability 2 study found an average short-term profit ROI of £1.87 per pound invested, rising to £4.11 with sustained effects. TV averaged £5.61 in full profit ROI. Use industry benchmarks as a guide, but measure against your own historical performance and specific business goals.
Should I handle media buying in-house or use an agency?
It depends on your scale, complexity, and internal capabilities. Agencies bring expertise, buying power, and tools. In-house teams offer control and brand knowledge. Many organisations use a hybrid approach. What matters most is having clear accountability for results, regardless of structure.
Which media channels deliver the best ROI?
There’s no universal answer. The Profit Ability 2 study found TV drives the highest overall profit volume (54.7%), whilst retail media offers closed-loop measurement. The best channel is the one that reaches your audience when they’re most likely to act. That varies by objective, audience, and creative.
From Cost to Growth Lever
Media buying is too often treated as an operational cost centre. In reality, it’s the growth lever that determines whether marketing spend compounds or disappears.
The future belongs to organisations that treat media buying as strategic capital allocation: aligning spend with business goals, activating the right data, and demanding evidence of return on investment.
Across this series, we’ve shown that in Part 1, media buying is not admin but a discipline that matters. In Part 2, the landscape is shifting fast, from AI to retail media to privacy considerations. And here in Part 3, that ROI isn’t a mystery. It’s the product of strategy, measurement and relentless optimisation.
The brands that thrive will be those that stop asking “What does media buying cost?” and start asking “What does media buying earn?”
Turn Your Media Investment into Measurable Growth
Getting media buying right requires strategic vision, rigorous measurement, and continuous optimisation. As a Fractional CMO, I help businesses build the frameworks and discipline needed to turn advertising spend into commercial results. If you’re ready to make every pound work harder, let’s talk about how to transform your media buying from a cost centre into a growth engine.
