1. The "was" price: is the comparison genuine?
A discount is only as honest as the price it is measured against. In the United States, the Federal Trade Commission's Guides Against Deceptive Pricing (16 CFR Part 233, in the Code of Federal Regulations since 1967) set out how a seller may compare prices. Section 233.1 covers the most common claim, a reduction from the seller's own former price.
Under the Guides, a former price is a fair basis for a comparison only if it is the actual, bona fide price at which the item was offered to the public on a regular basis for a reasonably substantial period of time. If the seller inflated the price only to advertise a big cut later, the "bargain" is false.
The Guides give a worked example. A retailer buys pens for $5 and usually sells them for $7.50, a 50 percent markup. He raises the price to $10 for a few days, knowing almost nobody will buy at that price, then advertises "Were $10, Now Only $7.50!". The Guides call this "obviously a false claim". The chart below shows why: the sale price is the regular price.
Other sections cover comparisons with other stores' prices (233.2), manufacturer list or "suggested retail" prices (233.3), and "buy one, get one" offers, where the price of the item you must buy should not be raised (233.4).
Europe is stricter and more precise. Since 28 May 2022, Article 6a of the EU Price Indication Directive (added by Directive (EU) 2019/2161) requires a shop that announces a price reduction to show the prior price, defined as the lowest price it charged in at least the 30 days before the reduction.
How to check a "was" price yourself
- Look at the price history, not the badge.
- Ask whose price it is. "Compare at", "list price" and "MSRP" are not the store's own former price.
- Check other stores. If everyone charges the "sale" price every day, the discount is not real.
2. The unit price: what are you really paying?
A percentage off tells you nothing about value. The number that does is the unit price: the price divided by the amount you get, per ounce, per count, per liter or per load. A "40% off" small pack can still cost more per ounce than the full-price large pack.
No federal law in the United States requires stores to show unit prices on shelf tags; some states and cities do. The National Institute of Standards and Technology (NIST) publishes a model Uniform Unit Pricing Regulation in NIST Handbook 130 and a best-practice Unit Pricing Guide for retailers (NIST Special Publication 1181, first published in December 2014 and updated in 2025).
- Compare the same unit. A shelf tag may show one product per ounce and the next per count. Convert first.
- A bulk pack is only cheaper if you use it all before it expires.
Discount and Unit Price Calculator
Enter the "was" price, the price you pay and the size for two items, in the same unit (ounces, grams or count). It runs in your browser; nothing is sent.
Method: percentage off = (was price − price paid) ÷ was price × 100. Unit price = price paid ÷ size.
3. The countdown timer: is the deadline real?
A clock that ticks toward zero pushes you to buy before you compare. Researchers call this a "dark pattern". A 2019 Princeton University study of about 11,000 shopping websites, "Dark Patterns at Scale" (Mathur and others), found countdown timers that reset or kept the same offer after they hit zero. The FTC's 2022 staff report "Bringing Dark Patterns to Light" names false urgency, such as fake countdown timers, as a deceptive practice.
A simple test: reload the page, open it in a private window, or come back the next day. If the timer starts again or the "ends tonight" price is still there, the deadline was not real.
Frequently asked questions
Is it illegal to show a fake "was" price?
In the US, the FTC Act forbids deceptive practices, and the FTC Guides Against Deceptive Pricing (16 CFR Part 233) say a former price must be one the item was really offered at, openly and for a reasonably substantial period. In the EU, the prior price must be the lowest price of at least the last 30 days.
Is a bigger percentage off always the better deal?
No. Compare the unit price. A smaller pack at 40% off can still cost more per ounce than a larger pack at full price.
How do I know if a countdown timer is fake?
Reload the page, open it in a private window, or come back later. If the clock restarts or the offer is still there after the deadline, the urgency is false.