Is this channel working? ROAS, and the margin it hides

Decide course — make the call

• Track: Marketing
• Difficulty: Beginner · 4/8
• Read time: ~16 min, then you make the call
• The concept: ROAS & channel contribution
• Scored decision — one defensible answer, reasoning shown. You pick the call; every wrong option shows what it costs you. This is a Decide course: you make a judgment, you don’t run code, and it is not a certification.
• ▶ Interactive model — a calculator on this page turns your own numbers into the decision, so you can stress-test the call yourself.

1. Before you start

ROAS — return on ad spend — is the revenue a channel brings in divided by what you paid to run it. Spend $1,000 on ads, get $3,000 of sales back, and the ROAS is 3.0: three dollars of revenue for every dollar of spend. It is the number every ad dashboard shows first, and it is only half of the story, because revenue is not money you keep. A sale at a 40% margin only leaves 40 cents of every dollar to pay for the ad and everything else.

Three honest statements before you start:

• This is a Decide course. You read a situation, learn the idea, and make a call. You do not write or run any code.
• The company below, Meadowlark Home, is composite — an invented online store built from ordinary figures so the arithmetic is clean. No number is a claim about any real firm.
• This is not a certification. It proves, to you, that you can defend a channel call.

You need only arithmetic. The hard part is judgment, not maths.

2. The Situation

Meadowlark Home sells rugs, throws, and cushions direct to shoppers online. Last month it put $30,000 into a Meta prospecting campaign that returned $60,000 in sales — a ROAS of 2.0 — and the growth lead wants to double the budget: “we’re getting two dollars back for every one, so more spend is more profit.” The finance lead wants it cut: “that channel is bleeding cash.” You have to make the call, and only one of them has done the arithmetic.

The catch is that the same 2.0 ROAS can add money or destroy it, and which one is true turns on a single number the growth lead never mentioned: the margin on what those ads actually sold.

3. What you’ll be able to do

After this course you will be able to:

• Compute a channel’s ROAS, and say plainly why it is a revenue number, not a profit number.
• Turn revenue into contribution by applying the product’s margin, and judge a channel on the money it keeps — not the money it books.
• Find the break-even ROAS for any margin, and name the ROAS below which a channel loses money no matter how good it looks.
• Decide whether to keep, cut, or reprice a paid channel, and name the one number that flips the answer.

4. Prerequisites & time box

Difficulty: 4 / 8 — a new-manager decision: a couple of interacting factors and one real judgment call, where the obvious answer is often the trap.

Time box: about 16 minutes of reading (measured), plus your own thinking time on the call. That is under the 25-minute cap for a concept course.

Free-tier honesty: no signup, no software, no GPU. You read and decide in the browser.

5. The case & where the numbers come from

Meadowlark Home is a composite online retailer: its order economics are built from ordinary figures a small direct-to-consumer store would recognise, chosen for clean arithmetic and not drawn from or claimed about any real company. The definitions — ROAS, contribution margin, gross margin, break-even — are standard and cited in section 11. Every figure below is an in-course assumption; every later number is computed from these.

Item	Figure
Average order value (revenue per order)	$80
Product cost (COGS) per order	$36
Pick, pack & shipping per order	$8
Payment processing + returns reserve per order	$4
Meta prospecting — ad spend last month	$30,000
Meta prospecting — revenue last month	$60,000
Google Shopping — ad spend last month	$10,000
Google Shopping — revenue last month	$45,000

6. The Concepts

ROAS

ROAS is revenue divided by ad spend. For Meadowlark’s Meta campaign: $60,000 ÷ $30,000 = 2.0. For its Google Shopping campaign: $45,000 ÷ $10,000 = 4.5. On the dashboard, both are “positive” and Meta looks like it is “doubling the money.” But ROAS is built from revenue, and revenue is the top line — it still has to pay for the product, the shipping, the card fees, and only then the ad. A ROAS of 2.0 tells you the channel booked twice its spend in sales; it does not tell you the channel made money. That is the number the growth lead stopped at.

Contribution margin

Contribution margin is what one order keeps after the costs that order causes — the cost of goods, the fulfilment, the card and returns cost. For a Meadowlark order: $80 − $36 − $8 − $4 = $32. As a rate, that is $32 ÷ $80 = 40%. So of every revenue dollar an ad brings in, only 40 cents is left to cover the ad spend and then add profit. This is the number the ROAS hides. A channel does not spend “revenue” to earn its keep — it spends real dollars, and it earns back only the contribution on the revenue it drives.

Channel contribution

Here is the move the whole course turns on: judge a channel on contribution earned minus ad spend, not on revenue over spend. Contribution earned is the margin rate times the revenue. For Meta:

• Contribution the channel earned: 40% × $60,000 = $24,000.
• Ad spend to earn it: $30,000.
• Channel contribution: $24,000 − $30,000 = −$6,000.

A ROAS of 2.0 that felt like “+100%” is actually a $6,000 loss. Doubling its budget doubles the loss. Now run Google Shopping the same way: 40% × $45,000 = $18,000 of contribution, minus $10,000 of spend = +$8,000. Same margin, same company, opposite call — and the ROAS dashboard had them looking like the same kind of “positive” channel. Keep and scale Google; cut or fix Meta.

(An interactive calculator sits here — enter a channel’s spend and revenue and the order’s cost lines, and it returns the ROAS, the contribution margin, the break-even ROAS, and the money the channel actually kept, with the keep/cut call.)

Break-even ROAS

You do not have to redo the whole subtraction to know where a channel tips from loss to profit. Channel contribution is zero when margin rate × revenue = ad spend, which rearranges to ROAS = 1 ÷ margin rate. At Meadowlark’s 40% margin, the break-even ROAS is 1 ÷ 0.40 = 2.5. Any channel below 2.5 loses money; any channel above 2.5 makes it. Meta at 2.0 is below the line — so it loses — and Google at 4.5 is well above it. The break-even ROAS is the single yardstick to tape to the dashboard: it turns “is 2.0 good?” into “2.0 versus 2.5 — no.” Change the margin and the yardstick moves: at a 25% margin the break-even ROAS climbs to 4.0, and even a 4.5 channel is barely ahead. The margin sets the bar; the ROAS only tells you whether you cleared it.

7. Your Call

You have seen how ROAS, contribution, and the break-even ROAS decide Meadowlark’s call. Now a different one lands on your desk.

Kettleback Coffee sells whole-bean coffee online on a subscription — a different composite company from Meadowlark’s one-off home-goods store. A first order is worth $40 in revenue at a 40% contribution margin (so $16 kept per first order). Last month its TikTok prospecting channel spent $20,000 and drove $30,000 of first-order revenue. The twist a subscription adds: each customer it wins goes on to place, on average, two more orders at the same $16 contribution, with no further ad spend. Rather than a plain keep/cut on the first month, your job is to decide whether TikTok is worth keeping once repeat orders are counted — and to name what would reverse that call.

How this differs from the taught case (the transfer): this is a different company in a different subject (a subscription coffee brand, not a one-off home-goods store), the figures are different so the arithmetic must be redone, and there is an added constraint — repeat purchases, so the decision is made on contribution across a customer’s orders, not one. The core concept is the same: judge the channel on contribution against ad spend, not on the revenue ROAS.

8. Self-check

Before you write the memo, make sure you can say each of these in one line:

• Why is “ROAS is above 1.0, so the channel is profitable” the wrong test?
• What single number turns a channel’s revenue ROAS into a keep-or-cut line?
• How does the break-even ROAS change when the margin changes — and which way?

If any is fuzzy, reread section 6 — ROAS, contribution margin, channel contribution, and the break-even ROAS are the whole course.

9. Stretch

Push the decision further on your own:

• Back at Meadowlark: at what ROAS would the Meta channel stop losing money at a 40% margin, and how much would revenue have to rise (at the same $30,000 spend) to get there?
• Meadowlark’s margin is really a range: a sale bought with a 20%-off code carries a 25% margin, not 40%. What does the break-even ROAS become, and what does that say about scaling a discount-led channel? (The genuinely harder one — the margin is not a constant.)
• Kettleback is thinking of a channel whose customers rarely reorder. Write the one sentence you would say to a growth lead who insists “a 1.5 ROAS channel is always worth scaling.”

10. Ship it — your decision memo

Write a one-page memo to Kettleback’s founder. State the call (keep TikTok for now: over three orders it contributes +$16,000 against a one-time $20,000 spend, even though its first-order ROAS of 1.5 is below the 2.5 break-even). Show the two-line arithmetic (first order 40% × $30,000 − $20,000 = −$8,000; lifetime 750 × 3 × $16 − $20,000 = +$16,000). Name what you rejected (judging the channel on revenue ROAS, and judging it on the first order alone) and why. Name the one thing that would change your mind (the repeat rate falling below what makes the lifetime contribution clear the spend). Keep it to a single page a founder grasps in two minutes. This memo is your own argued claim — not a credential.

11. Sources

Meadowlark Home and Kettleback Coffee, and every dollar figure attached to them, are composite — constructed for clean teaching arithmetic, not drawn from or claimed about any real company. The concept definitions used to reason about them are standard; references below.

Concept / claim	Source (publisher)	URL	Accessed
ROAS as revenue over ad spend (return on marketing investment)	Wikipedia — Return on marketing investment	https://en.wikipedia.org/wiki/Return_on_marketing_investment	2026-07-19
Contribution margin = revenue − variable cost	Wikipedia — Contribution margin	https://en.wikipedia.org/wiki/Contribution_margin	2026-07-19
Gross margin as a share of revenue	Wikipedia — Gross margin	https://en.wikipedia.org/wiki/Gross_margin	2026-07-19
Break-even where contribution covers cost	Wikipedia — Break-even point	https://en.wikipedia.org/wiki/Break-even_point	2026-07-19
Customer lifetime value across repeat orders	Wikipedia — Customer lifetime value	https://en.wikipedia.org/wiki/Customer_lifetime_value	2026-07-19

Next up

Finished this call? Continue the Marketing track:

LTV:CAC — what the ratio really tells you (and what it hides) →  ·  Browse all courses