Fazley RabbiCPM is what you pay for a thousand showings of your ad. CTR is the share of people who saw the ad and clicked. CPC is what each click cost. CPA is what each result cost, such as an order, a lead or a message. ROAS compares the sales your ads brought in with what you spent on them. Each one answers a different question, and read together they show where an ad is working and where money is leaking.
CPM: the cost of being seen
CPM stands for cost per mille, mille meaning a thousand. It is your spend divided by impressions, multiplied by a thousand. An impression is one showing of your ad on a screen, and the same person can create several impressions.
CPM mostly reflects competition and quality. It tends to rise when many advertisers want the same people, such as in the run-up to Eid, when your audience is very narrow, or when people hide or ignore your ad. How the Meta ads auction works explains why quality matters. A low CPM is not automatically good: cheap impressions in front of the wrong people are still wasted.
CTR: did the ad catch attention?
CTR, or click-through rate, is clicks divided by impressions. It tells you how well the ad and the offer made people want to know more.
Some platforms report more than one kind of click, for example every click anywhere on the ad versus clicks that actually go to your link. If you care about visits to a page or a chat, look at link clicks. A strong CTR with no sales usually means the problem is after the click, not in the ad.
CPC: the cost of a visit
CPC, cost per click, is spend divided by clicks. It is really CPM and CTR combined: if impressions are expensive, or few people click, each click costs more. So when CPC rises, check which of the two moved before you change anything.
CPA: the cost of a result
CPA means cost per acquisition, or cost per action. It is spend divided by the results you care about. The key is deciding what counts. Ads Manager may call a started chat a result, but a chat is not an order. Work out your cost per confirmed order and compare it with your margin; planning a budget from margin and cost per order walks through that.
ROAS: sales compared with spend
ROAS, return on ad spend, is the revenue from ads divided by what the ads cost. A ROAS of three means the ads brought in sales worth three times their cost.
ROAS is useful but easy to misread:
- Revenue is not profit. Product cost, packaging, delivery and courier charges all come out of that revenue.
- Cash on delivery changes the picture. If parcels are refused or returned, the sale the platform counted never became money. See measuring real profit after COD returns.
- Platforms count what they can see. Each platform credits itself for sales under its own rules, so two platforms can claim the same order. Your own order records are the final judge.
How the five connect
Think of them as a chain. People see the ad (CPM), some of them click (CTR), each click has a cost (CPC), some clicks become results (CPA), and results become revenue (ROAS). When something goes wrong, find the weak link.
| What you see | Where to look first |
|---|---|
| High CPM | audience too narrow, heavy competition, people hiding the ad |
| Low CTR | the image, the first line or the offer is not catching attention |
| Good CTR, high CPA | landing page, price, slow replies or a confusing order process |
| Good CPA, weak profit | margin, delivery cost, returns and cancellations |
Common traps
- Comparing CTR or CPA across campaigns with different objectives. They are optimising for different things.
- Judging after a single day. Numbers swing; look at a week or more.
- Chasing the cheapest clicks. Cheap clicks from people who never buy are expensive.
- Trusting reported purchases without checking your own delivery records.
A weekly habit
- Note spend, link clicks and results from Ads Manager.
- From your own records, note confirmed orders, delivered orders and returns.
- Work out the cost per delivered order and compare it with your margin.
- Find the weakest link in the chain and change one thing.
If your numbers look healthy in Ads Manager but your accounts disagree, this diagnosis checklist is a good place to start. For regular, hands-on help, see my social media and ads management service.