> ## Documentation Index > Fetch the complete documentation index at: https://docs.vortexiq.ai/llms.txt > Use this file to discover all available pages before exploring further. # Catalogue Drift vs Amazon, eBay > Same SKU listed at materially different prices on eBay vs Amazon UK. MAP / brand-consistency risk. How to read it, why it matters, and how to act on it. **Metrics type:** [Cross-Platform Metrics](/nerve-centre/overview#metrics-types-explained) • **Category:** [Marketplace](/nerve-centre/connectors#connectors-by-type) > Same SKU listed at materially different prices on eBay vs Amazon UK. MAP / brand-consistency risk. ## At a glance > Cross-platform SKU price comparison. Counts SKUs where the eBay listing price differs from the Amazon listing price by more than the configured drift threshold (default **15%**). The "MAP / brand-consistency" lens, drift signals either a stale listing on one channel, a deliberate-but-unmonitored channel pricing strategy, or a third-party reseller drifting under your floor. | | | | ------------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | **What it counts** | `COUNT(SKUs WHERE abs(eBay_price - Amazon_price) / Amazon_price > 15%)`. SKUs are matched by GTIN / EAN / MPN where available, fallback by exact title-and-brand match. | | **Listing-format scope** | eBay side: fixed-price (Buy It Now) only. Auction-format listings are excluded by definition (no fixed asking price). Best-Offer-enabled listings use the asking price for comparison. | | **GMV / fees framing** | The card surfaces price drift, not revenue. Each row may or may not be material in £-terms depending on velocity. Sort by Amazon-side velocity descending to prioritise. | | **Promoted Listings** | Promoted listings on eBay use the same listing price; promotion doesn't move the underlying price. Drift detection is unaffected. | | **Multi-site aggregation** | The card pairs each connected eBay `marketplaceId` with the corresponding Amazon marketplace (eBay UK ↔ Amazon UK, eBay US ↔ Amazon US, etc.). Cross-site comparisons (eBay UK vs Amazon US) are excluded by default; toggle per workspace. | | **Currency** | Comparison is per-currency-pair (GBP-GBP, USD-USD). Cross-currency comparisons do FX conversion at the daily rate; small currency-fluctuation drift is filtered out by the 15% threshold. | | **Best-Offer-resolved orders** | Not directly relevant; this card is listing-price-based, not order-based. Heavy Best Offer activity on a SKU can mean the *effective* eBay price is lower than the asking price, which the card doesn't see. | | **Refunds** | Not applicable. | | **Cancellations** | Not applicable. | | **Time window** | `30D` (rolling). The card refreshes daily and shows SKUs that have drifted at any point in the last 30 days, so transient drifts (a 24-hour reprice mistake) get caught. | | **Alert trigger** | `>10 SKUs drifting >15%` simultaneously. Drift threshold tunable; default 15% is a typical MAP-violation floor. | | **Roles** | owner, marketing | ## Calculation Calculated automatically from your eBay data. See the At a glance summary above for what the metric tracks and the worked example below for a typical reading. ## Worked example A UK consumer-electronics seller running ebay.co.uk + amazon.co.uk on a 1,200-SKU shared catalogue. Snapshot 28 Apr 26. | SKU | eBay UK price | Amazon UK price | Drift % | Velocity (Amazon, 30D) | Likely cause | | ------------------------ | ------------- | --------------- | ------- | ---------------------- | --------------------------------------------------------------- | | BLU-HDMI-2M | £8.50 | £12.99 | -34.6% | 480 units | eBay listing wasn't updated when supplier raised costs | | WIFI-RT-AC1200 | £45.00 | £39.99 | +12.5% | 220 units | Below alert threshold (under 15%); no flag | | HDMI-4K-3M | £19.99 | £14.50 | +37.9% | 65 units | eBay still using launch-month MSRP; Amazon repriced 3 weeks ago | | BT-SPK-MINI | £24.99 | £29.99 | -16.7% | 380 units | eBay running an old promo that wasn't taken down | | **Drifting SKUs (>15%)** | | | | **923 units** | **3 SKUs flagged** | Five things to notice: 1. **Three flagged SKUs represent 923 units of monthly Amazon velocity.** Per-SKU drift impact varies. BLU-HDMI-2M (480 u/mo, eBay 34% under Amazon) is the most material: if the seller ships 480 a month at £4.49 lower than Amazon, that's £2,155 / month of margin walked because eBay buyers can see they're getting a "deal" while Amazon buyers (or arbitrageurs) buy on eBay then resell on Amazon. 2. **Drift goes in both directions.** SKUs over-priced on eBay (HDMI-4K-3M, +37.9% over Amazon) lose sales to Amazon: Amazon-side velocity is 65 units; eBay-side velocity for the same SKU could be 5 to 10 units, suppressed by the price gap. The fix is repricing eBay down to match Amazon. 3. **Arbitrage risk on under-priced SKUs.** A 34% eBay-vs-Amazon gap on a high-velocity item invites arbitrageurs to scrape eBay listings and relist on Amazon at the gap. The seller's eBay storefront becomes a wholesale source for third-party Amazon resellers, this looks like demand but is structurally bad (the seller's Amazon Buy Box owners may now be the arbitrageur, not the seller). 4. **Promo tails are the most-common preventable cause.** Sellers run a 14-day Easter promo on eBay, set the eBay listing price 20% below Amazon, and forget to revert. The card catches this within the next 24-hour scan; without the card, expired promos can persist for months. 5. **MAP violations matter for branded resellers.** If the seller is an authorised reseller of a third-party brand, the brand's MAP (Minimum Advertised Price) policy may forbid pricing more than X% below MSRP. eBay listings drifting under Amazon often violate MAP first; brands monitor this and can revoke reseller status. Watch the [Catalogue Drift](/nerve-centre/kpi-cards/ebay/catalogue-drift-vs-amazon) card alongside any MAP-policy thresholds you've negotiated. ## Sibling cards merchants should reference together | Card | Why pair it with Catalogue Drift vs Amazon | | ----------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------- | | [Amazon Top SKUs Missing on eBay](/nerve-centre/kpi-cards/ebay/amazon-top-skus-missing-on-ebay) | Sister card; tracks SKUs Amazon-listed but absent from eBay (channel-coverage gap). | | [eBay vs Amazon Revenue Share](/nerve-centre/kpi-cards/ebay/ebay-vs-amazon-revenue-share) | The aggregate cross-platform revenue split. Drift contributes to share migration. | | [Top Listings](/nerve-centre/kpi-cards/ebay/top-listings-by-revenue) | High-velocity eBay SKUs are the priority for drift-fix; pair to identify which SKUs need attention first. | | [Listings Missing Attributes](/nerve-centre/kpi-cards/ebay/listings-missing-attributes) | Adjacent listing-quality issue. Often the same upstream PIM gap drives both. | | [Total Revenue](/nerve-centre/kpi-cards/ebay/total-revenue) | Economic context for the drift impact. | | [Marketplace Fees](/nerve-centre/kpi-cards/ebay/marketplace-fees) | Fee math differs by channel: eBay 12.9% blended vs Amazon 8 to 15% referral. Drift decisions should be net-of-fees aware. | | [Shopify Total Revenue](/nerve-centre/kpi-cards/shopify/total-revenue) | Triangulation: a SKU drifting on eBay vs Amazon is often also priced inconsistently on the Shopify storefront. Audit all three. | | [Amazon Total Sales](/nerve-centre/amazon/total_sales) | The Amazon side of the comparison. | ## Reconciling against the vendor's own dashboard **Where to look in eBay Seller Hub (eBay-side data):** > [Seller Hub → Listings → Active](https://www.ebay.com/sh/lst/active), current eBay listing prices. Sort by price descending or filter by category to spot-check. eBay alone doesn't show drift vs Amazon; this card is a Vortex IQ cross-platform composite. To reconcile manually, pull the eBay listing price from Seller Hub and the Amazon listing price from Amazon Seller Central per SKU. **Where to look on Amazon (Amazon-side data):** > [Amazon Seller Central → Inventory → Manage Inventory](https://sellercentral.amazon.com/inventory). Amazon listing prices. **Timing, settlement, and reporting-lag table:** | Topic | Detail | | ---------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | **Timezone** | Both eBay and Amazon prices are point-in-time snapshots; no timezone-bounded windows. The card refreshes daily at 03:00 UTC. | | **Settlement / payout impact** | Indirect. Persistent under-pricing on eBay relative to Amazon shifts margin away from the seller toward arbitrageurs / channel-cannibalisation. | | **Promoted Listings cost reporting lag** | Not applicable to drift detection. | | **API throttling** | Each side polls separately. eBay Sell Inventory API: 5,000 calls/day. Amazon SP-API: per-second per-resource throttle. Full catalogue scan typically completes within 4 hours; the card refreshes daily. | | **SKU matching cadence** | The matching index (GTIN / EAN / MPN, fallback to title-and-brand) is rebuilt nightly. New SKUs added to either platform appear in the comparison the next day. | **Why our number may legitimately differ from a manual cross-platform audit:** | Reason | Direction | Why | | ------------------------------ | ---------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | **SKU matching imperfections** | Either | Title-and-brand fallback matches can produce false positives (different SKUs with similar titles) or false negatives (same SKU with slightly different titles). Workspace settings allow enforcing GTIN-only matching for higher precision at the cost of coverage. | | **Promo/sale prices** | Either | Amazon's Prime Day or eBay flash-sale pricing creates transient drift; the 30D window catches multi-day drifts but may miss flash sales under 24h. | | **Currency conversion** | Within ±2% | Cross-currency comparisons (rare) use the daily FX rate; SKU drift within ±2% of the threshold may flip in/out of the alert from currency movement alone. | | **Refresh latency** | Up to 24h | Both eBay and Amazon prices are scanned daily; intra-day price changes lag the card by up to 24h. | **Cross-connector reconciliation against other connectors the same seller may run:** | Card | Expected relationship | What causes legitimate divergence | | ------------------------------------------------------------------------ | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------ | | [`shopify.total_revenue`](/nerve-centre/kpi-cards/shopify/total-revenue) | If the seller runs a Shopify storefront with the same SKUs, the Shopify price is a *third* data point. Drift between any two of (eBay, Amazon, Shopify) is the broader catalogue-pricing-consistency issue. | Use Shopify as the canonical source of truth if the seller runs DTC; align eBay and Amazon to it. | | [`amazon.total_sales`](/nerve-centre/amazon/total_sales) | The Amazon side of the comparison provides velocity context for prioritising which drifting SKUs matter most. | Velocity ranking is independent of price; high-velocity SKUs with small drift can outweigh low-velocity SKUs with large drift in £ impact. | ***
Same-shape cross-platform pattern (for sellers running multiple marketplaces) The same channel-price-consistency concern applies anywhere multi-channel selling is run. This is a Vortex IQ-defined composite; there is no native dashboard for it on either eBay or Amazon. The cross-link helps multi-marketplace sellers think about catalogue-pricing-discipline holistically. * [`amazon.total_sales`](/nerve-centre/amazon/total_sales), Amazon's revenue side of the comparison.
## Known limitations / merchant FAQs **What's the right drift threshold for my business?** Default is 15%. Tune lower (e.g. 10%) for branded MAP-policy resellers where small drifts are MAP violations. Tune higher (e.g. 25%) for clearance / liquidation sellers where channel-by-channel pricing flexibility is intentional. The threshold is workspace-configurable. **Why GMV-of-fees framing on a price-comparison card?** Because the *outcome* of drift is GMV migration. A SKU under-priced on eBay relative to Amazon will sell more on eBay (good for eBay GMV) but at thinner margin (bad for net), and create arbitrage opportunities (bad for long-term channel mix). The card surfaces the price gap; the GMV consequence is in [eBay vs Amazon Revenue Share](/nerve-centre/kpi-cards/ebay/ebay-vs-amazon-revenue-share). **Best Offer makes my eBay "effective price" lower than my asking price, does the card see this?** No. The card compares **listing prices** (what's displayed publicly), not **realised order prices**. If you accept Best Offers averaging 10% under asking, your *effective* eBay price is 10% lower than the card shows. For a fully-converged read, run the Vortex Mind investigation on the SKU; it pulls realised prices from order history. **My multi-site SKUs are matched incorrectly, what now?** SKU matching uses GTIN / EAN / MPN as the gold standard, with title-and-brand fallback. False matches happen when SKU titles are very similar across non-identical products (e.g. different sizes of the same model). Workspace settings let you enforce GTIN-only matching for higher precision at the cost of coverage; this is the recommended setting for branded resellers. **What if Amazon repriced via the Buy Box and my listing didn't?** Amazon's algorithmic Buy Box repricer can change a SKU's displayed price within minutes; the Buy Box winner's price is what buyers see. The card reads the Buy Box price by default. If you're not the Buy Box winner, your *own* Amazon listing price may differ from the Buy Box; toggle the workspace setting to compare against your-own-price instead. **Why doesn't FBA / FBM split appear here?** FBA / FBM is a fulfilment-method distinction, not a pricing one. Both FBA and FBM listings can use any price; the card compares displayed prices regardless of fulfilment method. **The card flagged a SKU because Amazon dropped 20% overnight, should I match?** Not automatically. Amazon's algorithmic price changes can be transient (a competitor briefly dropped, Amazon's repricer chased, then both reverted). Wait 48 to 72 hours before responding to a fresh drift alert; the card's 30D window will keep tracking the SKU. If the gap persists, then reprice or investigate. **Does this affect Promoted Listings ROI?** Indirectly. Under-priced eBay listings convert more easily but at lower margin; Promoted spend on under-priced listings has higher conversion but lower per-conversion profit. Over-priced eBay listings convert less easily; Promoted spend is wasted. Either way, drift degrades Promoted ROI; fix drift before scaling Promoted spend. **Action playbook when this card alerts (`>10 SKUs drifting >15%`):** 1. Sort the flagged-SKU list by Amazon-side velocity descending. Highest-velocity drifts first. 2. For each: check the eBay listing's recent price history (Vortex Mind can pull this). If a stale promo, revert. If no promo, match the Amazon price. 3. Pause Promoted spend on flagged SKUs until pricing is reconciled. 4. If the seller is a branded reseller with MAP policy, flag potential MAP violations to the brand-management team. 5. Set up the Catalogue Drift card as a daily-checked dashboard tile to catch new drifts within 24 hours of occurrence. *** ### Tracked live in Vortex IQ Nerve Centre *Catalogue Drift vs Amazon* is one of hundreds of KPI pulses Vortex IQ tracks across eBay and 70+ other ecommerce connectors. Nerve Centre runs the detection layer; Vortex Mind investigates the cause when something moves; Ask Viq lets you interrogate any number in plain English. [Start for free](https://app.vortexiq.ai/login) or [book a demo](https://www.vortexiq.ai/contact-us) to see this metric running on your own data.