Percent Off vs. Percent Of: The Pricing Math Mistake Costing Collections Merchants Money

A Single Number, Two Very Different Meanings

When you set up a collection-level or storewide offer rule in Lury, you enter one number: an acceptance percentage. It's the single most important field in the entire configuration, and it's also the easiest to get backwards. Here's the mental model that trips people up.

You might read "acceptance percentage" and think it means the percentage of the list price you'll accept — so setting it to 30 would mean "accept offers at 30% of list price or higher." That's not what it does. It actually means the percentage off list price you're willing to give — so 30 means "accept offers up to 30% off," which is 70% of list price.

Why This Matters More Than It Sounds

Get this backwards in the aggressive direction and the mistake is invisible — you're just leaving money on the table by accepting less of a discount than you meant to offer. Get it backwards in the other direction, and it's expensive.

Picture a merchant who wants to protect margin and thinks "I'll only accept offers at 90% of list price or higher — that's a tight floor." If they type 90 into the field expecting it to behave as a floor percentage, they've actually configured "accept up to 90% off." Every offer above 10% of list price gets auto-accepted. On a $200 product, that's honoring offers as low as $20 — automatically, with no review, at scale, across every order that comes in overnight.

The Formula, Spelled Out

Here's exactly how Lury calculates your accept price for a collection or storewide rule:

accept price = list price × (100 − your percentage) ÷ 100

Worked examples on a $100 product:

• Set to 10 → accept price is $90 (you're allowing up to 10% off)
• Set to 25 → accept price is $75 (you're allowing up to 25% off)
• Set to 50 → accept price is $50 (you're allowing up to half off)
• Set to 90 → accept price is $10 (you're allowing up to 90% off — almost certainly not what you meant)

The rule of thumb: lower number = smaller discount, tighter floor. Higher number = bigger discount, looser floor. If your instinct says "I want to be strict, so I'll set a high number," stop and re-read the label — you want a low number to be strict.

Why the Framing Isn't Just Semantics

This isn't a purely academic distinction. Research on discount framing consistently shows that how a percentage is presented changes how both merchants and shoppers reason about it — percentage-off framing shifts perceived value differently than amount-off framing, and larger discount percentages are processed differently than smaller ones even when the underlying dollar value is identical. The "percent off" framing is the one shoppers are used to seeing on sale tags — which is exactly why it's the framing Lury uses internally. It's the more intuitive number for a shopper reading "30% off." It's just not automatically the intuitive number for a merchant setting a floor.

How to Check Your Current Settings Are Right

Before you trust a collection or storewide rule with live traffic, do the arithmetic once by hand:

1. Pick a representative product and its list price.
2. Apply the formula above with your configured percentage.
3. Ask: "Am I comfortable selling this specific item at this specific dollar price, automatically, with no review?"

If the answer is no, lower the number. If you want a tighter floor than your current setting allows, the fix is almost always to decrease the percentage, not increase it.

The Bottom Line

Product-level rules in Lury let you set an exact accept price per variant, which sidesteps this entirely — worth doing for your highest-margin or highest-risk items. But for collection and storewide rules, remember: the number is how much you're giving away, not how much you're keeping. Double-check the math before you turn a rule loose on your whole catalog. Install Lury to configure your offer rules with confidence.