Black Friday advertising: in peak week, Meta CPM runs 51% above September. The calendar to buy before the spike and harvest during it.
Black Friday falls on November 27. Seven weeks from now. And like every year, I will get the same message around November 15: "our CPMs are exploding, what do we do?". By then, there is not much left to do. Black Friday advertising is not won during Black Friday week. It is won now, in October, while attention still sells at its normal price. By late November you can only do two things: harvest what you prepared, or pay full price to catch up on what you did not do.
Black Friday advertising: what peak week really costs
Let's start with numbers, because everyone talks about a "spike" without ever saying how big it is.
- Lebesgue, 2026 BFCM benchmark. In peak week, Meta CPM for the e-commerce stores it tracks sits 51% above its September level. The same impression, half as expensive again.
- GeistM, review published January 13, 2026. On its own campaigns: Meta CPM up 11% in the second half of November 2025, up another 11% in the first half of December, then down 10% in the second half. The pressure does not drop the day after Cyber Monday. It lasts until mid-December.
- Triple Whale, more than 33,000 shops. Over the BFCM 2025 weekend, 606.6 million dollars of ad spend analysed: a Meta CPM of 22.26 dollars, close to 8% above 2024. On Google, cost per acquisition rose 34.18% in a year and ROAS fell 21.09%.
- Meta, fourth-quarter 2025 results. Ad impressions up 18% year on year, average price per ad up 6%. Meta is selling more space and selling it at a higher price, at the same time.
Keep the order of magnitude in mind: in late November you pay roughly one and a half times the September price for attention, and a little more every year.
CPM goes up, acquisition cost goes down: the November paradox
This is what makes the subject interesting. In the same Lebesgue data, blended CAC in peak week is 15% lower. At Triple Whale, Meta ROAS over the weekend comes out at 2.26, up 3.18% year on year despite the CPM. The impression costs more and the customer costs less.
The explanation is one word: demand. People have decided to buy. In France, Criteo measured on November 28, 2025 transactions up 3% and revenue up 6% compared with Black Friday 2024, across several hundred online retailers. The Joko app, working from the transactions of more than a million users, found that 62% of shoppers use the event to get ahead on Christmas gifts.
But look at the word "blended". That CAC mixes paid media with everything else. And everything else weighs a lot: according to Klaviyo, email and SMS drove 42% of total revenue for its customer brands over the five days of BFCM 2025, and revenue from repeat customers grew 13.5%, faster than revenue from new buyers. CAC falls mostly for those who have a base to wake up. Why a CAC that relies on paid media alone keeps climbing is the subject of the scale-up gap: why your CAC explodes on Facebook.
One honest caveat: French demand is not taking off. Joko measured average spending of 236 euros over Black Week 2025, 1.3% more than in 2024, with volumes down 3%. The cake is barely growing. It is the slices that get redistributed.
Who pays for the CPM spike: brands without a customer base
Triple Whale split its BFCM 2025 data by brand size, and this is the table I show founders.
- Under 1 million dollars in annual sales: 66.05% of weekend revenue comes from new customers.
- Between 1 and 10 million: 55.61%.
- Above 10 million: the pattern flips, 54.69% of revenue comes from returning customers.
Translation. Big brands spend Black Friday re-engaging people they already know, by email, for next to nothing. Small ones go and find two thirds of their revenue among strangers, at the exact moment a stranger costs the most all year. This is not a fatality of size. It is a matter of preparation.
For Essity, a gamified social campaign delivered 14 million impressions and leads at around 6 euros, while building a first-party base the brand owns. That work is done off season, on social platforms, while the auction is quiet. The reasoning is in the end of third-party cookies and the revenge of first-party data. A contact collected in October can be re-engaged for free in late November. A stranger targeted in late November is paid for at peak rate.
Black Friday budget: the calendar I apply
Two data points set the tempo. According to Lebesgue, the median budget ramp starts 18 days before Black Friday, so November 9 this year. And according to Triple Whale, in the four days before the 2025 weekend, November 24 to 27, brands had already spent 396.6 million dollars, 65% of what they put into the weekend itself. Black Friday "week" really lasts three weeks. After November 9, you are bidding against everyone.
Until November 8: fill and test. A waiting list, early access, an alert: any mechanism that turns an impression into a contact. And your creatives tested now, on a small budget, so that you reach late November with known winners. Testing a creative at peak CPM means paying one and a half times the price for the lesson. The protocol is in pre-launch creative testing.
November 9 to 22: ramp up gradually. Early offers for your base, prospecting only on validated creatives.
Week of November 23: harvest. Email, SMS, retargeting, search on your brand name. No new audience, no new creative, no new campaign structure. And someone looking at the accounts every day, weekend included.
After December 15: resume prospecting. That is when GeistM sees CPMs ease by 10%.
My rule for a Black Friday budget
Half the budget committed before November 20, to fill a base and validate creatives. If more than half goes out between the Monday of Black Week and Cyber Monday, you are buying at peak price what you could have prepared at the normal price. Black Friday week is for converting people who already know you, not for introducing yourself.
Not selling anything on promotion? Step out of the auction
This is the case nobody covers. You are a fintech, a B2B SaaS, a subscription service. You do not do Black Friday. But on Meta, you bid in the same room as every online retailer in the country. You pay their peak CPM without having their demand peak: your prospect has not decided to change payroll software because it is November 27.
My advice: between November 23 and December 1, cut paid prospecting on social platforms, keep retargeting and brand search, and redeploy that budget from mid-December and in January. I have no public B2B benchmark to show you, so build your own: pull your CPMs and cost per lead week by week for November and December 2025. Ten minutes, and you will know.
And not every auction spikes the same way. In the Triple Whale data, TikTok CPM over BFCM 2025 fell 27.5% year on year and its ROAS gained 28.42%, for only 3.66% of spend against 67.6% for Meta. When two thirds of budgets fight in the same place, the placement next door is cheaper.
What I tell founders in early October
Your Black Friday is decided in the next four weeks. You will not negotiate the late-November CPM. What you control is how many people will already know you when it spikes, and how many creatives you will already know can sell. The brands that win in November are the ones that bought in October.
If you want to check your plan before the auction heats up, our free audit looks at how your budget is spread week by week. And to set the maximum CAC you can accept in peak week, the ROAS calculator gives you the threshold in two minutes.
