5% price increase on an underwear collection: no change in conversion
Commentary byLiftArchiveOur analysis, not theirsA 5% price increase on one SAXX performance underwear collection showed no statistically significant change in conversion rate over four weeks.
SAXX ran the test in-house on its US site, and it was published as a Shoplift case study.
We treat it as inconclusive: no drop was detected, but that is not proof of no effect.
- Conversion rate: no statistically significant difference between the two prices. This is a flat result.
- No figures were published for the conversion rates, sample size or revenue per visitor in each group.
- SAXX rolled the increase out in early December 2025 and reported no visible hit to conversion that month. That is a before-and-after observation, not part of the test.
The change
Only the prices on one collection change, by 5%.
Simplified mockup drawn by LiftArchive from the shared screenshots.
Control
One performance underwear collection at its existing prices on the US site.
Variant
The same collection with prices 5% higher, shown on every page where those products appeared, including cart and checkout.
Why it likely came out this way
Our reading of the result, not the practitioner's claim.
- A 5% rise on underwear works out to roughly a dollar or two per item, which may be too small for many shoppers to notice.
- SAXX sells on comfort technology and design, so its buyers may care less about small price moves than buyers of basic underwear.
- The test ran on a collection where SAXX sold a similar product at the same price, which gave a cleaner comparison but only covers one product line.
- A flat test can also mean the sample was too small to detect a modest drop.
Caveats: The result is flat, and no sample size or confidence interval was shared, so a small drop in conversion can't be ruled out. The test covered one collection on the US site over four weeks in late 2025.
Who ran it
SAXX ran this test for SAXX and published the results (Shoplift case study). The numbers are theirs; the summary and commentary on this page are ours.
Read the original case study on SAXX →
How to run this test on your store
- Hypothesis
- If we raise prices 5% on one collection, then conversion rate will stay about the same because our buyers value the product enough to absorb a small increase.
- Primary metric
- Revenue per visitor on the tested products
- Guardrails
- Conversion rate
- Units per order
- Share of shoppers switching to cheaper products
- Who should test it
- Premium brands facing cost or tariff pressure that need to know if a small increase will hurt sales. Plan for enough traffic to detect a small drop. It fits poorly if you sell commodity products where shoppers compare prices closely.
Questions
Does a small price increase hurt conversion?
Not always. In this SAXX test, a 5% increase on one collection produced no significant change in conversion over four weeks.
What does a flat price test mean?
It means the test did not detect a difference.
A small effect may still exist, so check how much traffic the test had before treating it as proof.
How should I pick products for a price test?
Pick a line with steady traffic and a clear comparison.
SAXX chose a collection where a similar product sold at the same price.
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