The Scale job, properly explained

Your ROAS going down might be your profit going up.

Scale is the job that gets misjudged most, because the metric that tells you if you're winning — blended ROAS — is exactly the number that hides whether your next pound is winning. Here's the mechanic, with real numbers.

Illustrative worked example built to demonstrate the mechanic — not a client's real figures.

The blended ROAS trap

Say a campaign is running at 300% ROAS — £10,000 spend, £30,000 revenue. The ad platform suggests increasing budget, projecting the account will settle at 270% ROAS once spend rises. That 270% figure looks like a small step down for more scale. It isn't what it looks like.

Stage	Spend	Revenue	ROAS
Current	£10,000	£30,000	300%
Platform's suggestion (blended)	£15,000	£40,500	270%
The incremental £5,000 — what's actually happening	+£5,000	+£10,500	210%

The point: the 270% you were shown is a blend of the £10,000 still earning 300% and the new £5,000 only earning 210%. The extra spend is real, but it's working far harder than the headline number suggests — and "harder" here means less profitably, not more.

Then the profit question — because 210% ROAS still isn't "profit"

210% ROAS on the incremental spend means every £1 spent returned £2.10 in revenue. Whether that's worth doing depends entirely on contribution margin — what's left after cost of goods, once ad spend is deducted. Here's the same £5,000 incremental decision at four different margin levels.

Incremental Profit = (Incremental Revenue × Contribution Margin) − Incremental Spend

The point: at a 30-40% margin, that "profitable-looking" 210% ROAS is actually a loss once the real cost of goods is factored in. The platform's suggestion would have you spending more to lose money faster.

Compare against your alternative, not your average

Now say there's a second option for that same £5,000 — a new US campaign, projected at 250% ROAS: £5,000 spend, £12,500 revenue. Compared to your current 300% blended average, 250% looks worse. Compared to the 210% you'd actually get by pushing more into the core campaign, it's the better job for that pound.

Option	Spend	Revenue	Incremental ROAS	Profit at 50% margin
A — Push more into core campaign	£5,000	£10,500	210%	£250
B — New US campaign	£5,000	£12,500	250%	£1,250

The point: a "worse" campaign against your average can still be the better decision — because the comparison that matters is against your next-best alternative, not your headline number. This is also why a single blended ROAS target across a whole account quietly punishes good decisions and rewards bad ones.

What this means for how Scale gets scored

A Scale campaign in a GOAS audit is never judged against a flat target. It's judged against the marginal economics of the next pound — and against its real alternatives — using contribution margin as the scoreboard, not the headline ROAS the platform shows you. This is the same discipline that made a JudeLuxe-style pitch land: not "trust the number," but "here's what the number is actually made of."

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