The Streetlight Effect: A businessman in business casual attire meticulously searches the ground directly under the bright glow of a streetlight, completely oblivious to a massive pile of cash sitting just feet away, hidden in the surrounding darkness.
You lost your wallet in the park. But you're searching under the streetlight — because that's where you can see. Sounds ridiculous, doesn't it? Marketing teams do this constantly.
They optimize clicks, impressions, and platform-reported returns. Not because those metrics drive profit — but because those are the ones they can measure. Meanwhile, the real levers sit in the dark. This is the marketer's dilemma: the metrics that are easiest to see are the least connected to the P&L, and the metrics that actually move the business require infrastructure most teams never build.
The seven levers sitting in the dark
Marketing results fully reconciled with the P&L. Connect every dollar spent to actual financial outcomes. If marketing's reported performance and the finance team's P&L tell different stories, neither is a basis for decisions.
Predictive LTV:CAC as the primary metric. Stop using backward-looking ratios that lie to you. A ratio built on last year's cohorts tells you what the business was, not where this month's spend is taking it.
A multi-attribution framework with incrementality testing. Know what's actually driving conversions, not what touched last. Last-click gives you a tidy answer; incrementality gives you a true one.
Real-time channel activation and server-side audiences. Act on signal while it's still fresh, not next quarter. The value of a signal decays fast; infrastructure that shortens the loop between insight and action is a compounding advantage over competitors reading last month's reports.
Rapid, data-driven marketing investment allocation. Move budget weekly based on performance, not annually based on politics. Annual budget cycles guarantee you'll overfund what worked last year and starve what's working now.
Dynamic budgeting and forecasting. Your plan should update as fast as your data does. A forecast that only changes at quarterly reviews isn't a forecast — it's a hope with a timestamp.
Fully loaded margin and CAC targeting. Optimize for profit per customer, not revenue per customer. A cheap customer who never repurchases and returns half their order isn't cheap — the fully loaded view is the only one the board actually cares about.
What this looks like in practice
We obsess over running this playbook with omnichannel retailers. In one recent deployment, it produced $14M in contribution margin in nine months. Not from spending more — from finally measuring what matters, and reallocating against those measurements at speed.
If your CFO still sees marketing as a cost center, this is why. You're reporting on impressions. They're asking about margin. The gap between those two conversations is exactly the set of levers above — and every one of them is an infrastructure decision, not a talent problem.
Stop searching where the light is. Start building the infrastructure to see the whole picture. The teams that win the next five years won't be the ones with the best creative or the biggest budgets — they'll be the ones whose measurement reaches into the dark where the profit actually lives.
David Manela is co-founder of Exactius, a growth and data science company. Follow him on LinkedIn for more frameworks on growth, marketing, and capital allocation.
David Manela
David Manela is the founder of Exactius and creator of the Growth Operating System — a framework for deploying capital-efficient, compounding growth inside scaling companies.
FAQ
Frequently asked
Why does my marketing team say ROAS is great when the P&L doesn't show it?
ROAS and the P&L measure different things. ROAS is platform-attributed conversion value divided by ad spend. The P&L shows recognized revenue after costs. The gap comes from costs ROAS leaves out, such as product, shipping and returns, and from attribution: each platform credits conversions under its own rules, so sales that would have happened anyway can still count toward its ROAS.
How do you measure the revenue marketing actually caused?
Use incrementality testing, which compares people or regions exposed to ads with a control group that was not. Google describes its Conversion Lift tool as measuring conversions directly driven by people seeing your ads, through user-based or geography-based studies, and notes it is not available in every account. The gap between platform-reported conversions and measured lift shows how much of a reported ROAS the ads caused.
What is fully loaded CAC?
Fully loaded CAC counts every cost of acquiring customers, not only media. Investor David Skok's SaaS definition divides total sales and marketing expenses, including salaries, by the number of new customers acquired. Paid-only CAC, which divides ad spend by new customers, will always look lower. The article argues that profit per customer on a fully loaded basis is the view the board cares about.
What is predictive LTV?
Predictive LTV estimates the value a customer will generate from early behavior, instead of waiting for a cohort to mature. Google Analytics 4 offers short-range versions, including purchase probability over the next 7 days and predicted revenue over the next 28 days, for properties with enough returning users. Longer-range models, such as the BG/NBD model published in Marketing Science in 2005, forecast repeat purchasing from recency and frequency.
What is the difference between ROAS and incremental ROAS?
ROAS divides all attributed conversion value by ad spend. Incremental ROAS divides only the conversion value the ads caused, as measured against a control group, by the same spend. When platform attribution credits conversions that would have happened anyway, incremental ROAS comes in below reported ROAS. It is the better basis for budget decisions because it reflects what the spend changed.
Related Reading
Keep going
Ready to fix the system?
Your growth system is either compounding or degrading.
Book a diagnostic call. We'll identify where your growth system is breaking and what it's costing you.