ROAS vs ROI: The Metrics That Actually Matter in Paid Social

Return on ad spend — revenue divided by spend — is the most quoted and most misused number in performance marketing. A 4.8× ROAS sounds excellent until you learn the margin is 20% and the campaign is quietly unprofitable.

ROAS tells you how efficiently the machine converts spend into revenue right now. It says nothing about profit, customer lifetime value, or whether you are just harvesting demand you already had.

Return on investment accounts for cost of goods, fees, and creative production. The formula that matters: (revenue × margin − total cost) ÷ total cost. A campaign at 3× ROAS with 60% margin beats one at 5× ROAS with 15% margin — every time.

If your reporting cannot answer "did this campaign make money after everything", you are reporting activity, not results.

1. Marginal CPA — what did the last conversion cost, not the average one. 2. New-customer ROAS — strip out retargeting so you see real acquisition efficiency. 3. Creative win rate — what share of new assets beat the incumbent. 4. Payback period — how many days until a cohort covers its acquisition cost.

These four numbers fit on one screen and drive every scaling decision: raise budgets when marginal CPA holds, refresh creative when win rate drops, extend payback tolerance when LTV supports it.

The goal of analytics is a decision: scale, hold, kill, or refresh. Every widget that does not feed one of those four actions is decoration. Ruthlessly delete it.