ROAS says how much revenue each unit of ad spend returned. The number that actually decides profitability is break-even ROAS: with a 40% margin you need at least 2.5, because 60% of revenue is already cost of goods.
Formula & methodology
ROAS = revenue ÷ spend (also shown ×100 as a percentage). Break-even ROAS = 1 ÷ margin — the revenue multiple needed so gross profit exactly covers the ad cost.
Worked example
Spend 2,000, revenue 10,000 → ROAS 5.0 (500%). With a 40% margin, break-even is 2.5: this campaign is profitably above it — a ROAS of 2.0 with the same margin would be losing money despite doubling spend into revenue.
Limits
Platform-reported revenue depends on attribution windows and can overcount. ROAS ignores lifetime value and organic effects. Assumptions, not promises.