ROAS vs profit: why a 3.1 ROAS can lose money

The short answer

ROAS is revenue divided by ad spend, so it says how much you sold per ad dollar. Profit is what stays after the product, the shipping, the payment fee and the ads are paid. A campaign can show a ROAS of 3.1 and still lose $2.39 on every order when the product is expensive to make and ship.

The same order, measured both ways

A $60 order won at a ROAS of 3.1 costs $19.35 in ads. What happens next depends on costs the ad dashboard never sees.

	Store A	Store B
ROAS	3.1	3.1
Left before ads	$33.96	$16.96
Ads for this order	−$19.35	−$19.35
Profit on the order	$14.61	−$2.39
POAS	1.75	0.88

POAS: profit per ad dollar

POAS is what is left of your orders before ads, divided by ad spend. Store A: $33.96 ÷ $19.35 ≈ 1.75. Store B: $16.96 ÷ $19.35 ≈ 0.88. The rule is simple: above 1.0 the ads pay for themselves, below 1.0 they do not.

POAS and break-even ROAS say the same thing in two ways. Store B’s break-even ROAS is 3.54, and 3.1 ÷ 3.54 ≈ 0.88.

Which one to steer by

Inside the ad account: ROAS is the number you have. Put your break-even ROAS next to it and it becomes a profit signal.
For decisions about budget: use profit after ads in money, per campaign. A campaign at ROAS 2.2 that keeps $800 beats one at 4.0 that keeps $90.
At month-end: profit after ads for the whole store, then fixed costs.

Questions

Can a high ROAS still mean a loss?

Yes. If your break-even ROAS is 3.54, a ROAS of 3.1 loses money on every order, however good 3.1 looks in the dashboard.

What is a good POAS?

Above 1.0 the ads cover themselves. How far above depends on your fixed costs and how much you want to keep.

Why does my ad platform’s ROAS differ from my store’s?

The platform counts orders it claims by its own attribution rules. Revenue ÷ spend from your store’s real orders is usually lower, and it is the one your bank agrees with.

Check it on your own numbers. The break-even ROAS calculator is free and needs no sign-up. ProfitNod works the same numbers out from your store’s real orders, inside Shopify.

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