Anchoring Bias Black Friday Case Study: How a $150 “Discount” Was Really $19
When the UK consumer group Which? tracked 201 Black Friday “deals” every day for a full year, it found that 99.5% of them were the same price or cheaper at some other point in the year. Only one product out of 201 was at its lowest price on Black Friday itself. That gap between what the sign says and what the price history shows is the anchoring bias Black Friday pricing is built on. This case study walks through one real purchase decision, the research behind why a strike-through price works so well, and a seven-step routine you can use on Black Friday (November 27 this year) and Cyber Monday to judge a discount against the price history instead of against the sign.
The Case: A $380 Pair of Headphones “Now $230”
Last November I had a pair of noise-canceling headphones sitting in a cart. The product page showed the familiar setup: a grey, struck-through “$379.99” next to a bold “$229.99,” with a red badge that said Save 39%. A countdown timer ticked underneath. My gut response was immediate: $150 off is a great deal, and it ends tonight.
I write software for a living, so my reflex when something feels too clean is to check the logs. In this case the logs were a price-history tracker. The $379.99 figure was the manufacturer’s launch price from well over a year earlier. Over the previous two months the headphones had sold for about $249 almost every day. Earlier that summer they had briefly dropped to roughly $230. So the real discount compared with the price anyone was actually paying was about $19, roughly 8%, not $150 and not 39%.
Nothing on that page was technically false. The $379.99 really had been a price at some point. But the number did its job: it set the reference point my brain used to judge everything after it. That is the whole mechanism of anchoring, and it is why I now treat every Black Friday strike-through price as a claim I have to check, not a fact I can trust.
The Anchoring Bias Black Friday Pricing Is Built On
Anchoring is the tendency to lean heavily on the first number you see when you estimate a value, even when that number is irrelevant. Amos Tversky and Daniel Kahneman showed it in their 1974 paper in Science, “Judgment under Uncertainty: Heuristics and Biases.” Participants watched a wheel of fortune land on a number, then estimated the percentage of African countries in the United Nations. People who saw the wheel stop at 10 gave a median estimate of 25%. People who saw it stop at 65 gave a median of 45%. A random spin moved their answers by 20 points.
The effect gets stronger when the anchor is a price. In a 2003 study published in the Quarterly Journal of Economics, Dan Ariely, George Loewenstein, and Drazen Prelec asked 55 MIT MBA students to write down the last two digits of their Social Security number, then to say how much they would pay for items such as a cordless keyboard, wine, and Belgian chocolates. Students whose digits fell in the top fifth were willing to pay $55.64 on average for the keyboard. Students in the bottom fifth would pay $16.09. Across the six products, the top group’s valuations were typically around three times higher, and the only difference between the groups was a number that had nothing to do with keyboards.
Retail pricing applies this lab result at scale. The “was” price, the “compare at” price, and the manufacturer’s suggested retail price are all anchors. They show up before the sale price, they are bigger than the sale price, and they turn the question “Is $229.99 a good price for headphones?” into the much easier “Is $229.99 less than $379.99?” The answer to the second question is always yes. If you want the broader catalog of these retail techniques, our breakdown of framing effect pricing psychology and the six retail tactics behind it covers the companion biases that often appear on the same product page.
The legal line: “former price” has a definition
In the U.S., the Federal Trade Commission’s Guides Against Deceptive Pricing (16 CFR 233.1) say a former price is a legitimate basis for a comparison only if it was “the actual, bona fide price at which the article was offered to the public on a regular basis for a reasonably substantial period of time.” In practice, enforcement is uneven, and a price that was charged briefly or long ago can still show up as a strike-through. The rule tells you what an honest anchor should be. It does not guarantee that the one in front of you meets that standard.
The Data: How Big Black Friday Discounts Really Are
The spending numbers explain why retailers work so hard on the anchor. According to Adobe Analytics, U.S. shoppers spent a record $11.8 billion online on Black Friday 2025, up 9.1% from the year before, and $14.25 billion on Cyber Monday. Across the five days from Thanksgiving through Cyber Monday, online spending reached $44.2 billion. The National Retail Federation counted a record 202.9 million shoppers over that weekend, spending an average of $337.86 each on holiday-related purchases, up from $315.56 in 2024.
Real discounts do exist. Adobe reported these peak Cyber Monday 2025 discounts off listed prices by category:
| Category | Peak discount off listed price | What to check before buying |
|---|---|---|
| Electronics | 31% | 90-day low on a price tracker, not MSRP |
| Toys | 28% | Prices at two or three other retailers |
| Apparel | 25% | How often the brand runs “sitewide” sales |
| Computers | 23% | Model year: older stock is often the “deal” |
| Televisions | 22% | Exact model number, including retailer-specific variants |
| Furniture / Appliances | 19% | Delivery and haul-away fees that offset the discount |
| Sporting goods | 17% | End-of-season clearance timing |
Two things stand out. First, these are peak discounts, the best offers in each category, not averages. Second, they are measured against the listed price, which is exactly the number an anchor-savvy retailer controls. The Which? price-tracking work points the same way from the other direction: its study of Black Friday 2020 found that 92% of deals were the same price or cheaper in the six months before the event. If most of the discount was already available in July, the Black Friday sign is mostly telling you about the anchor, not about the price.
Why the Cost of Getting It Wrong Is Bigger Than the Price Tag
A $19 deal dressed up as a $150 deal is annoying. It becomes expensive when the anchor pushes you into buying things you had not planned on, and then financing them. LendingTree’s survey of the 2025 season found that 37% of U.S. consumers took on holiday debt, averaging about $1,223, with credit cards the most common way people borrowed. The Federal Reserve’s G.19 release puts the average commercial bank credit card rate at 22.36% for accounts that are being charged interest (Q3 2026).
Run the math on that average balance at that rate:
| Payoff timeline on $1,223 at 22.36% APR | Monthly payment | Total interest paid |
|---|---|---|
| 3 months | $422.95 | $45.86 |
| 6 months | $217.33 | $80.99 |
| 12 months | $114.68 | $153.14 |
Stretch the payoff over a year and the interest (about $153) wipes out a typical “real” discount on several purchases. My headphones would have saved $19 against the going price. Carried on a card for a few months, that saving disappears completely. The same logic applies to split-payment checkouts, which Adobe says drove $1.03 billion of Cyber Monday 2025 spending alone. We dig into why those plans cost more than the fees suggest in our piece on buy now pay later hidden costs.
There is also a liquidity angle. The Federal Reserve’s most recent Survey of Household Economics and Decisionmaking found that 63% of adults would cover a hypothetical $400 emergency with cash or its equivalent, which means more than a third would not. For anyone in that group, a well-anchored impulse purchase isn’t just a budgeting mistake. It eats into the buffer that keeps a car repair from turning into debt.
How to Beat Anchoring Bias on Black Friday: A 7-Step Routine
You can’t switch anchoring off. Research going back to Tversky and Kahneman shows that even people who know about the bias still get pulled by it. What works is replacing the retailer’s anchor with your own before you see theirs. Here is the routine I’ve used for the past few seasons:
- Write your list before you open a single ad. Only items you would have bought this winter at full price go on it. This is the most important step, because an anchor can’t persuade you to buy a product you were never going to consider. If impulse purchases are your weak spot all year, our guide to how to stop impulse buying online has a cost formula that works well here.
- Set your own anchor: a maximum price per item. Decide what each item is worth to you, in writing, and do it now. A self-set ceiling is the counter-anchor. When the sale page loads, you compare against your number, not theirs.
- Pull a 90-day price history. Use a price tracker or the retailer’s own price history where one exists. The useful benchmark is the lowest price in the last 90 days and the typical price over that period. The launch MSRP is almost never the right comparison.
- Calculate the “real discount.” Real discount = (typical 90-day price − sale price) ÷ typical 90-day price. My headphones: ($249 − $229.99) ÷ $249 ≈ 7.6%. If the real discount is under about 10%, the urgency is manufactured, and you can usually get that price again in the next few months.
- Check two other retailers and the exact model number. Big-box retailers sometimes sell slightly different model numbers of TVs and appliances for the holidays, which makes direct price comparisons harder. Matching the exact model keeps you from comparing against a fake benchmark.
- Ignore timers and stock counters for 24 hours. Countdown clocks add urgency on top of the anchor. A one-day cooling-off rule takes away the urgency. If the deal is real it is very likely to come back on Cyber Monday, and Which?’s data suggests similar prices tend to show up again within months.
- Pay only with money already in your budget. Give the holiday its own spending line, ideally funded from a sinking fund, and pay in full by the statement date. If the purchase only works with financing, it doesn’t fit the budget, however big the discount looks.
Not sure how much holiday spending your budget can absorb this month?
A note on automating step 3
Because I’m an AI and automation nerd, I eventually stopped checking prices by hand. A simple price alert on the handful of items on my list does most of the work. I set the alert at my self-chosen maximum, and if it never fires, I don’t buy. It is the same principle as auto-investing into an index fund: take the decision away from the moment when your judgment is weakest. The anchor still shows up on the page, but by then the decision has already been made somewhere else.
Where Anchoring Bias Follows You After Black Friday
The skill transfers. The same reference-point trick that makes $379.99 feel relevant to a $229.99 sale also shows up when a list price frames a negotiation, as we cover in our deep dive on anchoring bias when buying a house. It shows up in salary offers, car dealer “invoice” prices, and the “starting at” price on a subscription tier. In each case the fix is the same as on Black Friday: set your own number from independent data before you see the other side’s anchor, and judge the offer against your number.
The honest conclusion from my own headphone experiment is that Black Friday isn’t a scam. Some prices really are at their yearly low that weekend, and the Adobe category data shows real money is on the table. But the headline percentage tells you almost nothing about whether you have found one of them. The price history does.
Key Takeaways
- The anchoring bias Black Friday retailers rely on makes strike-through prices feel like the true value, even when that price was charged only briefly or long ago.
- In Which?’s year-long tracking of 201 Black Friday deals, 99.5% were the same price or cheaper at another time of year.
- Arbitrary numbers can roughly triple what people are willing to pay (Ariely, Loewenstein & Prelec, 2003), so knowing about the bias is not enough on its own.
- Judge a deal by its real discount against the 90-day typical price, not against MSRP or the “was” price.
- Set a written maximum price per item before you shop, so your anchor comes first.
- Financing wipes out most real discounts: $1,223 at 22.36% APR costs about $153 in interest if it takes 12 months to pay off.
Sources: Which? (Black Friday 2020 price-tracking study, published November 2021); Adobe Analytics 2025 holiday shopping data; National Retail Federation Thanksgiving weekend survey (December 2025); LendingTree holiday debt survey (2025 season); Federal Reserve G.19 Consumer Credit release (November 2026); Federal Reserve, Economic Well-Being of U.S. Households in 2025 (May 2026); Tversky & Kahneman, Science (1974); Ariely, Loewenstein & Prelec, Quarterly Journal of Economics (2003); FTC Guides Against Deceptive Pricing, 16 CFR 233.1.
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