David Ogilvy, the legendary adman who built one of the world’s most successful agencies, famously said that too many people use data “as a drunk uses a lamppost: for support rather than illumination.”

Early in my career, a CFO stopped me mid-presentation: “I don’t trust the numbers you’re showing me.”

I was initially taken aback and tried to defend my position…but he was right. I was Ogilvy’s drunk – leaning on data that made marketing look good rather than using it to illuminate what the business should do differently. My dashboards cherry-picked metrics that justified our existence, not insights that would help us grow faster or win more deals.

I lost some credibility that day.

And without trust and credibility, you can’t drive strategic decisions. You’re stuck defending your existence rather than improving it.

The Credibility Crisis (And Why It’s Getting Worse)

According to Gartner’s 2024 CMO Survey, marketing budgets have dropped to around 7% of overall company revenue. Meanwhile, a significant chunk of B2B marketing teams admit their business doesn’t trust their measurement capabilities.

This creates a vicious cycle: Reduced budgets → pressure for immediate results → shortcuts in measurement → reduced credibility → further budget cuts.

I’ve watched this play out for 20 years. The marketing leaders who survive, and more importantly thrive – who actually get resources and influence – aren’t the most charismatic presenters. They’re the ones who can prove impact with numbers that finance, sales and the business actually trust.

What Actually Matters: Stop Measuring What’s Easy

Nobody outside marketing cares about email open rates. The CEO doesn’t lie awake worried about website bounce rates. Your CFO couldn’t care less about brand awareness unless you can connect it to deals closing faster. If they do…think hard about your current place of employment!

The metrics that build trust connect marketing to business outcomes in language that sales and finance already speak:

Lead-to-customer conversion by source: Which channels produce leads that become customers versus leads that waste everyone’s time? I once watched a marketing team celebrate 10,000 webinar registrations while their sales team complained that webinar leads never converted. The conversion data told the real story: 0.3% became qualified pipeline deals versus 8% from referrals. That’s not a success story – it’s a resource allocation problem.

Customer acquisition cost by channel: What does it actually cost to acquire one paying customer through each marketing investment? Not what you spent on the channel – what you spent per actual customer. Include everything: agency fees, tool costs, internal salaries, the lot. I’ve seen marketers hide software costs to make CAC look better. It works until finance audits the budget, then you’ve destroyed trust forever.

Marketing-influenced pipeline: What’s the total value of opportunities where marketing played a meaningful role? And I mean meaningful – not “someone from that account visited the website once” but actual engagement that moved deals forward.

Sales cycle impact: Do marketing-touched deals close faster? This translates directly into sales efficiency. At one company, marketing-influenced enterprise deals closed 35% faster. That unlocked budget – we weren’t just generating leads, we were making sales more efficient.

The Attribution Trap (And How to Escape It)

Attribution is one of the main credibility killers for Marketing teams

Traditional lead attribution misses B2B buying complexity entirely. Someone downloads a whitepaper, gets marked as marketing-sourced, but sales had been nurturing that account for six months. Marketing claims credit. Sales gets annoyed. The CEO thinks we’re all idiots.

But complex multi-touch attribution requiring a PhD to understand also fails because nobody trusts what they can’t comprehend.

The solution isn’t perfect attribution – it’s honest attribution.

Stop trying to prove marketing “caused” every deal. Instead, show marketing’s influence while admitting what you can’t prove:

“This data shows strong correlation between marketing activity and pipeline growth. We can’t isolate marketing’s specific contribution – sales hired three excellent reps this quarter and the market shifted – but here’s what the patterns suggest…”

That builds more trust than claiming perfect accuracy when everyone knows it’s bollocks.

Use different models for different purposes, and explain what each shows:

• First-touch for top-of-funnel budget justification – shows initial contact but ignores nurture
• Multi-touch for understanding the complete journey – though it can over-credit minor touches
• Time-decay for long sales cycles – gives recent activity more weight than 18-month-old touchpoints

Transparency builds trust. Mystery breeds skepticism.

When Your Numbers Get Challenged (And They Will)

Sales teams will challenge marketing data. Finance will question your ROI. Your response determines whether challenges build better measurement or destroy credibility.

When Sales Questions Your Data:

Don’t get defensive. Nothing kills trust faster than marketing leaders acting like their numbers are beyond scrutiny.

Get collaborative instead: “You’re right that these numbers don’t match your experience. Let’s dig into why. Either our tracking is missing something, or there’s a disconnect we need to fix.”

I’ve seen this transform critics into allies. When sales helps identify tracking gaps or attribution issues, they become stakeholders in accurate measurement rather than skeptics of whatever marketing reports.

At one company, sales insisted our “marketing-sourced” numbers were inflated. Instead of arguing, we invited them to audit our attribution methodology. They found legitimate gaps – accounts where sales had relationships pre-dating marketing touchpoints. We fixed the tracking. Our numbers went down 20%, but our credibility went up 200%.

When Finance Questions Your ROI:

CFOs speak a different language. Translate:

Cost per acquired customer with clear methodology showing exactly what you included. One CFO asked me, “Does this include salary?” I’d missed it. He knew. That destroyed six months of trust-building.

Customer lifetime value impact: Do marketing-sourced customers have higher LTV? Lower churn? At one SaaS company, we discovered marketing-sourced customers had 40% lower churn in year two. That single insight justified a budget increase because it connected marketing to long-term business value, not just acquisition costs.

Payback periods by channel: How long until marketing investment pays for itself? Finance teams understand this immediately. “Webinars have a 4-month payback, trade shows take 14 months” is a conversation finance wants to have.

The Mistakes That Kill Credibility

The Vanity Metrics Trap:

I’ve sat through presentations where marketing leaders spent 20 minutes on website traffic and social engagement, then rushed through pipeline impact in 90 seconds. If a metric doesn’t connect to revenue, it doesn’t belong in a business review.

Data Perfection Paralysis:

Waiting for perfect measurement while business leaders question your value is career suicide. Start with defendable data and improve over time. “Our attribution captures 85% of touchpoints based on spot-checking against sales notes. Here’s our improvement plan for the remaining 15%” is infinitely better than “we’re still building our framework” six months in.

Perfect measurement doesn’t exist. Useful measurement does.

The Causation Claim:

“We launched a campaign and pipeline increased 25%, therefore our campaign drove it.”

Maybe. Or maybe sales hired three excellent reps. Or maybe the market shifted. Or maybe a competitor went bankrupt.

I once presented exactly this correlation as causation. The COO asked one question: “What evidence do you have that it was your campaign and not the price cut we implemented the same week?” I had none.

Always explain what data suggests versus proves. Show correlation honestly. Admit confounding factors. Your credibility depends on it.

What Actually Works

The marketing leaders I’ve seen succeed do two things consistently:

Show your working. Explain methodology clearly enough that non-marketers understand how you calculated metrics. I include a one-page “How We Calculate This” appendix in every board deck. It’s boring. Nobody reads it most months. But when someone has a question, it’s there, and that builds trust.

Demonstrate predictive value. Don’t just report what happened. Forecast what’s likely based on current data: “Based on current pipeline velocity and historical conversion rates, we’re tracking 15% below Q4 target. We need either £2M more top-of-funnel by end of month, or we shift budget to accelerate mid-stage deals. Given our conversion rates, I recommend the latter – here’s the expected impact…”

That’s not reporting. That’s strategic contribution.

From Support to Illumination

That CFO was right to challenge my numbers. I was using data to justify decisions I’d already made, not to make better decisions.

The numbers I presented weren’t technically wrong. But they weren’t connected to anything that would help us grow faster, win more deals, or serve customers better. I was measuring marketing activities while leadership needed insights to drive business decisions.

I stopped trying to make marketing look good and started trying to help the business make better choices. The data got uglier – our influence was smaller than I’d claimed, our efficiency was lower than I’d hoped. But it became useful.

Within six months, we had budget increases because leadership trusted that when I said “invest here,” the recommendation was based on what worked, not what made my team look good.

Data credibility isn’t the end goal. It’s the foundation that lets you actually improve the business rather than constantly defend your department’s existence.

Marketing leaders who can prove impact with honest numbers get resources to drive growth. The alternative is tactical execution while wondering why nobody takes you seriously.

The measurement infrastructure to track these metrics systematically requires investment – in tools, in process, in discipline. But the credibility it builds is what transforms marketing from a cost center that gets cut first to a growth driver that gets invested in.

That’s the difference between a lamppost for support and a lamppost for illumination.

Godspeed.