Every ad number, explained like you're new.

Marketing isn't creativity. It's arithmetic with money attached. Every metric below is one number divided by another — and each one tells you exactly where to look next.

I'll use one campaign the whole way through. You spend $100. Here's what happens to it. The numbers are made up so the arithmetic is easy to follow — they're not results from anyone's account.

The journey of $100

• 12,500 impressions — times your ad appeared on a screen. That's a CPM of $8.
• 250 clicks — people who tapped it. That's a CTR of 2%, and a cost per click of $0.40.
• 200 landing page views — the ones whose page actually loaded. 80% of the clicks survived.
• 20 leads — people who filled the form. That's a cost per lead of $5.
• 2 clients — people who actually paid. That's $50 to get a customer.
• $2,000 revenue — at $1,000 each. That's 20× back on the money you put in.

What each word actually means

CPM is what it costs to be seen a thousand times — $100 ÷ 12,500 × 1,000 = $8. It rises when lots of advertisers want the same people.

CTR is how many people tapped, out of everyone who saw it — 250 ÷ 12,500 = 2%. This one is about your ad, not your audience. A low CTR is almost never a targeting problem.

CPL is what one interested person cost you — $100 ÷ 20 = $5. And CAC is what one paying customer cost — $100 ÷ 2 = $50. CAC is the number that decides whether you have a business; CPL just tells you how the ads are doing.

ROAS is the simplest one: money out divided by money in. $2,000 ÷ $100 = 20×.

The only formula worth memorising

Cost per lead = CPM ÷ (1,000 × CTR × conversion rate). In our campaign: 8 ÷ (1,000 × 0.02 × 0.08) = $5. The conversion rate there is measured from clicks — 20 leads ÷ 250 clicks = 8%.

There are only three ways to make leads cheaper. Every tactic you'll ever read about is one of those three wearing a costume.

• Pay less to be seen — lower the CPM
• Get more people to tap — raise the CTR
• Get more of them to fill the form — raise the conversion rate

Finding the broken step in 30 seconds

Read the numbers top to bottom and stop at the first one that looks wrong. That's your actual problem — everything below it is just a symptom.

• CPM high? Too many advertisers chasing the same people, or your audience is too narrow.
• CPM fine but CTR low? Your ad is the problem — the hook, the first frame, the first line. Not the targeting.
• CTR fine but few page views? Your page is slow. They tapped and left before it loaded.
• Page views fine but no leads? The page or the offer. They read it and weren't convinced.
• Leads fine but no sales? Not an ads problem at all. Follow-up speed, or the sales conversation.

The number the platform shows you is not the number

This is the one that costs people real money. Ad platforms count conversions generously — they'll claim a lead that never reached your CRM, count one person twice, or take credit for someone who was coming anyway. In accounts I've audited, the platform's reported count has run far above what the CRM actually received.

If the platform reports double the leads you really got, your cost per lead looks half what it is. Then you scale it — because the fake number says it's working.

The fix is one habit: count your leads in your CRM, not in the ads dashboard, and divide spend by that. Every number on this page should be calculated from the system where the money and the actual humans are.