ROAS - Return on Ad Spend

ROAS answers: for every dollar I put into this ad, how many dollars of revenue came back? A ROAS of 4 means $4 of revenue for every $1 spent.

ROAS is channel-specific and campaign-specific. Your Meta ROAS and your Google ROAS are different numbers and should be tracked separately. Blending them hides which channel is actually working.

ROAS is a revenue metric, not a profit metric. A ROAS of 4 sounds good but if your COGS and shipping eat 70% of revenue, you are losing money on every sale. That is why contribution margin and MER matter more for profitability decisions.

New-customer ROAS is a separate and usually harder metric than blended ROAS. Returning customers who would have bought anyway inflate blended ROAS. Some brands track only new-customer ROAS for their acquisition campaigns to avoid this flattery.