CPM, CPC and CTR

Also called Cost per mille, Cost per click, Click-through rate, Impressions

The three numbers every advertising report leads with, and none of them is a business outcome.

What it means

CPM is the cost per thousand impressions — what you pay to be seen, whether or not anyone acts.

CPC is the cost per click — what you pay for one person to arrive.

CTR is the click-through rate, the percentage of impressions that produced a click.

Why it matters

They are useful for diagnosing an advert. A low CTR usually means the creative or the targeting is wrong; a high CPC usually means a competitive auction.

They are not useful as the headline of a report, and that is exactly where they usually appear. An excellent CTR on adverts that generate no enquiries is a well-optimised failure.

What it looks like in practice

Read them in order and stop at the first bad one. Impressions low? Budget or targeting. CTR low? Creative or relevance. Clicks high but enquiries low? The landing page or the offer.

Always end at cost per enquiry and cost per customer. Those are the two numbers that connect to the business.

What to watch out for

Reports that stop before the outcome. If an agency reports impressions and clicks but not enquiries, ask why — usually the answer is that the tracking was never set up.

Comparing CTR across platforms and formats. They are not comparable in any useful way.

Where to get proper advice

Whoever runs your advertising should be able to show the whole chain from impression to customer. If they cannot, that is the finding.