Why does CPM go up in November?

Around major shopping events many brands raise budgets at once and compete for the same audiences, so auction prices typically climb. Plan for higher costs, test creative earlier and lean on audiences and offers that convert well enough to stay profitable at higher CPMs.

Is a low CPM always good?

No. A low CPM can mean you are reaching people who rarely click or buy, or showing up in cheap placements few people notice. Judge CPM together with click-through rate and cost per purchase.

Cost per mille (CPM)

CPM (cost per mille) is the price an advertiser pays for 1,000 ad impressions, calculated as ad spend divided by impressions, multiplied by 1,000.

What is CPM?

CPM stands for cost per mille, mille being Latin for thousand. It is the price you pay for your ad to be shown one thousand times. Social platforms such as Meta and TikTok mostly run on an impression auction, so CPM is the basic price of reaching people there. CPM matters because it sets the floor for every other cost. If reaching a thousand people gets more expensive, your cost per click and cost per purchase usually rise too, unless your ads get better at turning views into clicks and sales. Watching CPM helps you tell whether rising costs come from the market or from your own ads.

How to calculate CPM

Divide ad spend by the number of impressions, then multiply by 1,000. For example, if you spend $50 and your ad is shown 10,000 times, the CPM is 50 divided by 10,000, which is 0.005, times 1,000, which gives $5. If the same $50 only buys 5,000 impressions next month, CPM has doubled to $10. Note that impressions count every time the ad is shown, including repeat views to the same person. Reach counts unique people. If frequency is high, your CPM can look fine while you keep showing the ad to the same small group.

What is a good CPM?

There is no universal good CPM, because it typically varies a lot by platform, country, audience, placement and time of year. Wealthier countries and narrow, in-demand audiences usually cost more to reach. CPM often rises sharply in the weeks before major shopping holidays, when many advertisers compete for the same people. A higher CPM is not always bad. A pricier audience that buys often can be more profitable than a cheap one that never converts. Track your own CPM over time and judge it together with click-through rate and cost per purchase rather than in isolation.

How to lower CPM

Give the platform room to find people: broader audiences usually cost less per impression than very narrow ones. Use a mix of placements instead of forcing one expensive slot. Create ads that people actually engage with, because platforms tend to reward relevant ads with cheaper delivery. Refresh creative before frequency climbs and people start hiding or ignoring the ad. Plan for seasonal spikes by building audiences and testing creative before busy periods. And remember the real goal is profitable sales, so accept a higher CPM when the audience converts much better.

CPM vs CPC

CPM is what you pay to be seen, and CPC is what you pay to be clicked. CPM depends mostly on the auction and your audience. CPC depends on CPM and on how compelling your ad is, measured by click-through rate. For example, at a $5 CPM, an ad that gets 1% of viewers to click produces 10 clicks per thousand impressions, so each click costs $0.50. If creative improves and 2% click, the CPC halves to $0.25 even though CPM stays the same. That is why better creative usually beats chasing cheaper impressions.

Questions

Why does CPM go up in November?: Around major shopping events many brands raise budgets at once and compete for the same audiences, so auction prices typically climb. Plan for higher costs, test creative earlier and lean on audiences and offers that convert well enough to stay profitable at higher CPMs.
Is a low CPM always good?: No. A low CPM can mean you are reaching people who rarely click or buy, or showing up in cheap placements few people notice. Judge CPM together with click-through rate and cost per purchase.