Anchoring Bias
Anchoring bias is the tendency to over-weight the first number a shopper sees. On a product page, that first number quietly sets the rules for every comparison that follows.
Anchoring Bias
The cognitive tendency to over-weight the first number a shopper sees when judging price, value, or quantity.
Anchoring bias is one of the most replicated findings in behavioural economics: when people evaluate an unknown quantity — fair price, reasonable shipping fee, sensible bundle size — they latch onto whatever number was presented first and adjust from there, usually not far enough. On a product page, the anchor is rarely the price you want the visitor to pay. It is the strikethrough RRP, the premium tier shown above the standard one, or the €4.99 shipping fee that makes free over €50 feel generous.
As a sub-type of cognitive biases applied to e-commerce, anchoring is the lever that converts a flat catalogue into a structured choice architecture. Used well, it raises average order value without changing the underlying product.
The mechanism is automatic and largely unconscious. Tversky and Kahneman's original 1974 experiments showed people anchoring on numbers they knew were random — a spun wheel — when estimating unrelated quantities. Online shoppers are no different: the first price they see becomes the reference point against which every later price is judged cheap or expensive.
On a Shopify product page this shows up in three patterns. A strikethrough RRP next to the live price anchors perceived discount. A three-tier pricing card with the premium plan on the left anchors the standard tier as 'reasonable'. A €4.99 default shipping rate anchors the free-shipping threshold as obvious value. Each pattern is the same bias wearing different clothes.
Perceived Discount % = (Anchor Price - Sale Price) / Anchor Price * 100
Anchor Price
Reference price shown first
Typically the strikethrough RRP, MSRP, or 'compare at' price displayed adjacent to the live price.
Sale Price
Actual price the shopper pays
The live, transactable price on the product page.
Perceived Discount %
Discount the shopper feels they are getting
Almost always higher than the underlying margin sacrifice, because the anchor sets the comparison frame.
An apparel store sells a wool coat for €180. They display 'RRP €240' as a strikethrough above the price.
Anchor Price (RRP): €240
Sale Price: €180
→ Perceived Discount = 25%
The shopper feels they are saving 25% off retail, even though €180 is the store's standard price all season. The anchor — not the actual margin — is doing the work. Removing the strikethrough in an A/B test typically drops conversion 8-15% on fashion SKUs in this price band.
The size of the lift depends on which anchor pattern you use and where it sits on the page. Strikethrough pricing works hardest on considered purchases (apparel, beauty sets, small electronics). Decoy tiers work hardest on subscription and bundle pages. Shipping anchors work hardest at checkout, where the shopper is already committed and the basket value is fixed.
Typical conversion-rate uplift from common anchoring patterns on Shopify stores
| Anchor Pattern | Where It Appears | Typical CR Uplift | Best-Fit Vertical |
|---|---|---|---|
| Strikethrough RRP next to sale price | Product page, above price | +6% to +14% | Apparel, beauty, accessories |
| Premium tier shown first (left) | Subscription / bundle selector | +9% to +18% on mid tier | Skincare refills, supplements, coffee |
| Decoy product (worse value) | Variant or size selector | +5% to +11% on target SKU | Electronics, home goods |
| High default shipping → free over X | Cart / checkout | +4% to +9% AOV | Apparel, beauty, food |
| 'Was €X, now €Y' in email subject | Lifecycle email | +12% to +22% CTR | All DTC verticals |
Anchoring is also one of the easiest biases to mis-use. Inflated RRPs that no one ever paid attract consumer-protection scrutiny under EU Omnibus rules, which require the lowest price from the prior 30 days as the reference. The bias still works inside the rules — you just have to anchor on real numbers, not invented ones.
Frequently asked questions about anchoring bias
It is the tendency to treat the first number you see as the 'right' ballpark, even when that number is arbitrary. In e-commerce, the first price a shopper encounters quietly sets the rules for every comparison they make afterwards on the page.
Anchoring is a sub-type within the broader cognitive biases family. Where biases like loss aversion or social proof operate on emotion or peer signals, anchoring works purely on numerical reference points. It is the most reliable lever for influencing perceived price and value.
It works, consistently. A/B tests on apparel and beauty stores typically show 6-14% conversion uplift when a credible strikethrough is added next to the live price. The effect drops sharply if the anchor looks invented — shoppers discount anchors that are too good to be true.
Use a number with a real basis: the supplier RRP, the price you charged last quarter, the equivalent product at a competitor. EU Omnibus rules also require the lowest price from the prior 30 days as the reference, which keeps you compliant and credible.
Directly adjacent to the live price, with the anchor visually de-emphasised (smaller, strikethrough, lighter weight). The closer the two numbers sit and the faster the eye can compare them, the stronger the perceived-discount effect.
Yes, and often more powerfully than on one-off SKUs. Showing the annual plan first anchors the monthly plan as the 'reasonable' middle option. Three-tier layouts with the premium tier on the left typically shift 9-18% of buyers up to the mid tier.
It can. Anchors that feel fabricated (a €499 RRP on a product that has always sold for €99) trigger scepticism and hurt trust. Aggressive anchors also attract regulatory attention under EU and UK consumer-protection rules. Test, do not assume.
Run an A/B test where the control hides the anchor (no strikethrough, single-tier pricing) and the variant shows it. Measure conversion rate and AOV. Two to three weeks of traffic is usually enough on a top-50 SKU to reach significance.
Yes. A €4.99 default shipping fee anchors the free-shipping threshold as good value, which lifts AOV by 4-9% on stores that switch from flat-free to threshold-free. The anchor at checkout is the shipping number itself, not the product price.
Codes stack on top of an existing anchor, so the perceived discount compounds: a 20% code on a product already anchored against an RRP feels far bigger than 20% off a flat price. This is why 'extra X% off sale' email subject lines outperform straight-percentage offers.
Get an AI expert review of your site
Paste your URL — Metricuno's AI runs the same heuristic checks a senior CRO consultant would, scoring your page and prioritising the fixes that'll move conversion fastest.