CPM — Cost Per Mille

Cost Per Mille — what you pay for 1,000 ad impressions.

What it means

CPM stands for Cost Per Mille. "Mille" is Latin for thousand. So CPM is the amount you pay for every 1,000 times your ad is shown on a screen. Each showing is called an impression.

With CPM, you are paying for visibility, not for clicks. People may see your ad and never click, and you still pay for those views.

How it works

To calculate CPM, divide your ad spend by your impressions, then multiply by 1,000.

CPM = (total ad spend ÷ total impressions) × 1,000

Platforms like Meta Ads Manager and Google Ads show CPM in your campaign reports. On these platforms, the price is shaped by an auction. When many advertisers want to reach the same audience at the same time, such as during Diwali sales, CPM can go up. When there is less competition, it can come down.

A simple example

Meena owns a saree shop in Chennai. She runs an Instagram ad to announce her new silk collection. She spends ₹1,500, and the ad is shown 60,000 times.

Her CPM is (₹1,500 ÷ 60,000) × 1,000 = ₹25.

Why it matters

CPM is the main number for awareness campaigns. When your goal is to make lots of people know about your brand, a new shop, or an event, you care about reach more than clicks.

CPM also helps you compare platforms and audiences. If one audience costs much more per 1,000 impressions, you can ask whether it is worth the extra money.

But cheap impressions shown to the wrong people are wasted.

Beginner tips

• Use CPM-focused campaigns when your goal is awareness, not direct sales.
• Check CPM alongside CTR to see if people actually care about your ad.
• Refresh your creative when the same audience keeps seeing it again and again.
• Common mistake: judging a sales campaign only by low CPM instead of by conversions.

Related: Impressions, CPC, CTR