Revenue generated for every unit of currency spent on advertising.
Return On Ad Spend is total revenue attributed to advertising divided by the ad spend that produced it, usually written as a ratio like 4:1 or a percentage. A ROAS of 4 means four in revenue for every one spent. It is the headline efficiency metric for most paid campaigns.
Crucially, ROAS is a revenue measure, not a profit measure. It ignores product costs, fulfilment, and overheads, so a campaign can hit a strong ROAS and still lose money. It also depends entirely on the attribution model behind the revenue figure.
ROAS lets you compare campaigns, channels and audiences on a like-for-like efficiency basis and is the natural target for automated bidding. Your break-even ROAS depends on your margins, so a target that works for one business fails for another.
Treating ROAS as profit, ignoring the attribution window that inflates or deflates it, and optimising to ROAS while cannibalising sales you would have won anyway. Pair it with margin and customer lifetime value for a real picture.
Return on ad spend — revenue generated per dollar of ad spend — is the headline efficiency metric for paid media, answering "is this advertising making money?". A 4:1 ROAS means $4 back for every $1 spent. It is more intuitive than cost per acquisition for revenue-focused teams and is the metric most ad platforms optimise toward. But ROAS is a gross, revenue-based figure — it ignores margin, so a high ROAS on a low-margin product can still lose money, which is why it must be read against your break-even ROAS, not an arbitrary target.
The number that matters is not "is ROAS high?" but "is ROAS above break-even?" — and break-even depends on your gross margin. A business with 25% margins needs roughly a 4:1 ROAS just to break even, so a "healthy-looking" 3:1 is actually a loss. Two other blind spots: ROAS is usually last-click, so it under-credits upper-funnel channels that assist conversions, and it counts revenue not profit, so scaling a high-ROAS but low-margin product can still erode the bottom line. Sophisticated teams pair ROAS with margin-adjusted (profit) ROAS and multi-touch attribution.
A retailer celebrates a 3:1 ROAS on a campaign — until someone calculates break-even. The products carry a 25% gross margin, which means each sale only yields 25 cents of margin per revenue dollar, so the campaign needs roughly a 4:1 ROAS just to cover the ad cost. At 3:1 it is quietly losing money on every order. Two further checks sharpen the picture: the ROAS is last-click, so an upper-funnel awareness channel that assisted many of these conversions is being under-credited and looks worse than it is, and scaling this low-margin product would deepen the loss even as revenue grows. The team recalculates around break-even and profit-based ROAS, adjusts targets by margin, and uses incrementality tests to value the assisting channel properly. The lesson: a ROAS number is meaningless without your margin — always compare it to break-even, not a generic benchmark, and remember it counts revenue, not profit.
Part of our defined terms knowledge graph — browse every entry in this branch.
The average amount you pay each time someone clicks your ad.
Assigning credit for a conversion across the touchpoints that led to it.
The ratio of a customer’s lifetime value to the cost of acquiring them.
A root-level file that tells crawlers which URLs they may or may not fetch.
The underlying goal behind a search query, which content must satisfy to rank.
Common questions
Straight answers on how this fits your marketing and build.
Still have questions? Talk to a specialist