POAS vs ROAS - revenue is not profit
The two metrics share a denominator and differ only in the numerator, but that single difference changes everything. POAS = profit / ad spend, while ROAS = revenue / ad spend. ROAS counts the top line: it treats a one-pound sale on a 70 percent margin product exactly like a one-pound sale on a 10 percent margin product, even though the second keeps a fraction of the money. POAS strips that revenue back to the profit that actually survives, so it answers the question a finance director cares about - not how much did we sell, but how much did we keep.
The gap between the two is rarely small. A campaign reporting a comfortable 4.0 ROAS on products carrying a 30 percent gross margin is, before any other costs, only earning around 1.2 in profit per pound of spend. ROAS makes the campaign look like a clear winner; POAS shows it is barely past break-even. Reading revenue as if it were profit is one of the most common ways a paid media report flatters a campaign that is not really paying its way.
Why ROAS can hide weak profit
Revenue is gross by nature, and four things sit between it and the money you keep. Margin is the first: low-margin SKUs can post enormous revenue while contributing almost nothing. Fees are the second - payment processing, marketplace commissions and platform charges all skim the top before anything reaches the bottom line. Discounts are the third, and the most deceptive: a promotion can lift ROAS precisely because the price cut drives more units, while that same cut quietly erases the profit behind every order.
Returns are the fourth. A sale that is refunded a fortnight later still counts toward this month’s revenue and ROAS, even though it added nothing - and in categories like apparel the return rate can run well into double digits. Stack these four together and a campaign can show a healthy ROAS while its real contribution is thin or negative. POAS closes that gap by measuring the outcome after margin, fees, discounts and returns, which is why it is far harder to fool than a revenue-based ratio.
Break-even POAS
Break-even POAS is the simplest threshold in the whole framework: it is always 1.0. At a POAS of 1.0 each pound of ad spend returns exactly one pound of profit, so the advertising washes its face and contributes nothing above its own cost. Below 1.0 the campaign is losing money on a contribution basis; above 1.0 it is genuinely adding profit. This is cleaner than the equivalent revenue threshold, because break-even ROAS changes with every product’s margin - a 30 percent margin item breaks even at roughly 3.3 ROAS, a 50 percent item at 2.0 - whereas break-even POAS is one no matter what you sell.
That stability is what makes POAS a good target to optimise toward. Setting a POAS floor of, say, 1.5 gives every channel and product the same comparable hurdle, so you can rank them on contribution rather than on a revenue multiple that means something different in each catalogue line. For the full profit-first treatment of the concept, see profit on ad spend.
Why POAS matters most in ecommerce
Ecommerce is where the ROAS-versus-POAS gap does the most damage, because the three things that bend the two apart all run hot at once. Catalogues mix products with wildly different margins, so revenue is a poor proxy for contribution. Discounting is near-constant - sale events, codes and bundle offers - so a rising ROAS during a promotion can disguise a falling profit. And return rates are material enough to matter in the maths rather than the footnotes.
Optimising a paid budget on ROAS in that environment pushes spend toward whatever drives the most revenue, which is frequently the discounted, low-margin, high-return lines - the exact opposite of what a profit-led plan would choose. POAS realigns the budget with the bottom line, and you can put a figure on it directly with the POAS calculator. It is the natural companion to a forecasting approach that allocates by marginal return rather than headline revenue.
Related terms
- profit on ad spend - the full profit-first treatment of measuring advertising by contribution, not revenue.
- ROAS - revenue divided by ad spend, the top-line ratio POAS corrects for margin and costs.
- break-even ROAS - the revenue multiple needed to cover costs, which shifts with every product’s margin.
- marginal ROAS - the return on the next pound of spend, the metric that should drive scaling decisions.
Frequently asked questions
What is POAS?
POAS stands for profit on ad spend. It is the gross profit generated for every pound of advertising spend - calculated as profit divided by ad spend rather than revenue divided by ad spend. Where ROAS tells you how much revenue a campaign produced, POAS tells you how much money you actually kept after the cost of goods, fees, discounts and returns are removed.
How is POAS calculated?
POAS is gross profit divided by ad spend. To get gross profit you start from revenue and subtract the cost of goods sold, payment and platform fees, shipping, discounts applied and the value of returns, then divide what remains by the advertising spend that produced it. A POAS of 2.0 means every pound of ad spend generated two pounds of profit; a POAS of 1.0 means the campaign exactly broke even on a contribution basis.
What is the difference between POAS and ROAS?
ROAS is revenue divided by ad spend; POAS is profit divided by ad spend. ROAS treats a one-pound sale on a 70 percent margin product the same as a one-pound sale on a 10 percent margin product, even though the second keeps far less money. POAS strips revenue back to the profit that survives margin, fees, discounts and returns, so it reflects the commercial result rather than the top line.
Why should ecommerce track POAS?
Ecommerce catalogues mix products with very different margins, run frequent discounts and carry meaningful return rates, so revenue is a poor proxy for what a campaign earns. A promotion can lift ROAS while the discount quietly erases the profit behind it. Tracking POAS keeps the focus on contribution, so budget flows to the products and channels that actually grow the bottom line rather than the ones that simply move the most revenue.
Can a campaign have good ROAS but poor POAS?
Yes, and it is common. A campaign can post a strong ROAS while selling low-margin products, leaning on heavy discounts, or driving sales that are later returned - all of which inflate revenue without adding profit. The headline ROAS looks healthy, but once margin and costs are deducted the POAS can sit near or below break-even. That is exactly why ROAS alone can hide a weak commercial result.