The short answer
- Don't run price tests over BFCM. Shoppers compare prices more that week than any other, share screenshots, and check your ads against your store. Rules on reference prices and ad feeds also bite hardest around a sale.
- If you want an answer on price this year, test in October on full-price products that won't be in the sale, and end the test well before 16 November.
- Expect to detect only large effects on a handful of products. A price test sees only the traffic to the tested product pages (Example below).
- Judge on profit per visitor, never on conversion rate. A higher price usually sells fewer units and can still earn more.
- End the test and check that prices are restored before you build your sale discounts on top of them.
Who this is for: Shopify brands doing $1M to $10M a year that are wondering whether to change prices before or after the sale.
This is information about how the rules work, not legal advice. Check your situation with whoever advises you on consumer law.
The 2026 timeline
| When | What to do |
|---|---|
| By Wed 21 Oct | Start any price test you still want this year. Only on products you won't reduce in the sale. For products sold into the EU, a test inside the 30 days before an announced reduction can change the prior price you must show. |
| By Fri 6 Nov | End it, even if inconclusive. Check that every price is back where it should be. |
| 9 Nov to 15 Nov | Set sale discounts on top of the final prices. Check your Shopping feed matches the store. |
| Mon 16 Nov | Freeze. No price changes until after Cyber Monday except the planned sale. |
| From January | The quieter months are the time for wider price tests. |
Why not over the peak
Comparison shopping. In sale week shoppers open several stores side by side and come back to yours more than once. A shopper who sees $68 on Tuesday and $72 on Thursday, because they landed in a different test group on another device, has a reason to distrust the sale.
Reference prices in the EU. Directive (EU) 2019/2161 added Article 6a to the Price Indication Directive (98/6/EC). An announced price reduction must show the prior price, which is the lowest price the trader applied in a period of at least 30 days before the reduction. If your Black Friday reduction starts on Friday 20 November, those 30 days run from 21 October to 19 November. A price test that charged some shoppers a lower price in that window raises a question about what your "lowest price" was. The simplest way to avoid the question is to run no price tests on products you sell into the EU in the 30 days before a reduction you'll announce.
Former-price comparisons in the US. The FTC's guides on deceptive pricing (16 CFR 233.1) treat a former price as a fair basis for comparison when 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. A price that only some shoppers saw for two weeks is a weak "was" price.
Ad feeds. Google Merchant Center asks that the price in your product data match the price on your landing page and at checkout. Shoppers who arrive from a Shopping ad and see a different price create a mismatch.
What to test in October instead
- Full-price products that won't be discounted. Bestsellers you keep at full price through the sale, or new products launched this autumn. Their price answer is useful in December too.
- Compare-at presentation. Showing or hiding a genuine "was" price, on products where you have one. Shopify checkout doesn't show strike-throughs, so this only changes the product and collection pages.
- Price endings such as $48 against $49, on a small set of products, if you'll use the answer in January.
Keep a price test separate from your offer test (part 4). Shoppers who see a tested price and a tested offer at the same time make both results harder to read. If you need both in one comparison, a combined test gives each version its prices, offer and shipping from one assignment.
Step 1: Break-even for a price change
A price change pays if the change in margin per unit outweighs the change in units sold.
Illustrative inputs, not data from a real store. Plain arithmetic, with the same costs at both prices.
Inputs: a product with a 50% gross margin at today's price.
- An 8% price rise. Margin per unit goes from 50% to 58% of today's price. You can sell up to 13.8% fewer units and still earn the same gross profit.
- A 10% price cut. Margin per unit falls to 40% of today's price. You need 25% more units to earn the same.
The asymmetry is why a price cut needs a large response to pay, and why a modest price rise is often worth testing. See price elasticity for the term.
Step 2: Check what your traffic can detect
A price test only sees visitors to the tested products. That is usually a fraction of the store.
Illustrative inputs. Computed with the same sample-size formula Benchmyrk's planner uses (95% confidence, 80% power, two versions, even split).
Inputs: the tested products' pages get 1,500 visitors a day in total, and 3.5% of those visitors buy one of them.
| Test length | Smallest change in conversion rate the test can detect |
|---|---|
| 14 days | 21.4% |
| 21 days | 17.3% |
| 28 days | 14.9% |
A 13.8% drop in units is the break-even for the 8% rise above. Even four weeks can't reliably detect a change that size here. Expect "inconclusive" unless the effect is large, and decide in advance what you'll do then (keep today's price is the safe default before a sale). Profit per visitor needs more visitors than conversion rate, so the profit result will be less certain still. The sample size guide explains why.
Step 3: Run it cleanly and end it on time
- Primary goal: profit per visitor. Conversion rate usually falls when a price rises; that alone says nothing about profit. See revenue per visitor vs conversion rate.
- Guardrails: checkout completion and refund rate.
- Run whole weeks. No verdict before 7 full days; plan for three or four.
- Schedule the end for no later than Friday 6 November (in Benchmyrk, through the in-app assistant or the API; at that time the test completes, and a store price it raised is put back). That gives a week to restore prices, update feeds and set sale discounts on top.
- After it ends, open each tested product in Shopify and check its price, compare-at price and your Shopping feed.
Mistakes to avoid
- Testing a product that will be in the sale. Its test result and its sale result can't be separated.
- Different prices for shoppers who arrive from Shopping ads. Check the feed rule before you launch.
- Judging on conversion rate. A price rise that loses 5% of units can earn more.
- Leaving the test running into the freeze. Prices should be final before the sale discount is set on top of them.
- Strike-throughs that aren't genuine "was" prices. They must be prices you actually charged.
Checklist
- Tested products are full price and not in the sale.
- Break-even worked out for each tested price.
- Planned length from the calculator, ending by 6 November.
- Products sold into the EU checked against the 30-day prior-price window.
- Shopping feed setup checked for the tested products.
- Profit per visitor as the primary goal, with product costs set up.
- Prices, compare-at prices and feeds checked after the test ends.
More on the mechanics: price testing, and how price testing works on Shopify without Plus.
Advising clients on price tests? The agency track on the BFCM hub covers legal, ad-feed and reputation checks. The full season plan is in What to test before Black Friday and Cyber Monday on Shopify.