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Metrics type: Key Metrics • Category: Marketplace

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At a glance

A burst alert that fires when more than 3 of your top-revenue ASINs lose Buy Box in the same 24-hour window. Designed to catch coordinated reseller attacks, FBA-replenishment failures, and account-health-driven Buy Box throttling before the revenue impact hits the headline.

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Calculation

Calculated automatically from your Amazon (Selling Partner) data. See the At a glance summary above for what the metric tracks and the worked example below for a typical reading.

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Worked example

A UK Amazon-first DTC homewares brand. 110 active ASINs on amazon.co.uk. The brand woke up to this alert at 07:14 BST on 16 May 26, with the dashboard showing 5 top-revenue ASINs lost Buy Box overnight. The drill-down: Five things to notice that are specific to Amazon:
  1. Buy Box loss = sales loss, instantly. Within 6 hours of the alert firing, Total Revenue for the affected ASINs collectively dropped 67% vs the prior day’s same-hour baseline. Speed of response is the entire game; an alert acted on at 07:30 saves significantly more revenue than the same alert acted on at 17:30.
  2. Three different root causes, three different fixes. The five ASINs split into: 3 reseller pricing attacks (B07HOM0001, 0002, 0004), 1 inventory failure (B07HOM0003), 1 hijacker (B07HOM0005). Each needs a different response. The pricing attacks are addressable via temporary re-pricing or by reporting the reseller to Brand Registry. The inventory failure needs a same-day expedite to FBA. The hijacker needs a Brand Registry takedown request and is the slowest fix (2 to 7 days).
  3. Commission erodes 12 to 15% of headline, but the alert is about Buy Box not fees. Fees are commercial; this alert is performance. Don’t chase fee optimisation while ASINs are losing Buy Box; the cost of inaction on Buy Box loss dominates any fee saving by an order of magnitude.
  4. Amazon-first buyers don’t migrate to your DTC site. The brand sent a same-day Klaviyo campaign promoting the affected products on their Shopify store. Click-through was 1.7%, conversion was 0.4%. The Amazon-shopper cohort is functionally separate from the DTC cohort. The Shopify campaign generated £620 of recovered revenue against the £38,420 trailing-30D Amazon book at risk.
  5. Out-of-stock punishes you for weeks. B07HOM0003 (the inventory-failure ASIN) recovered Buy Box within 4 days of replenishment, but its organic search rank took 17 days to fully recover. Daily revenue for that ASIN ran 30 to 45% below baseline for the full 17 days even after Buy Box returned. The alert caught the failure fast; the cost was still in the thousands of pounds because Amazon’s organic-rank recovery is slow.

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Sibling cards merchants should reference together

This alert is the wake-up call. Pair it with these to triage:

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Reconciling against the vendor’s own dashboard

Where to look in Amazon Seller Central: Amazon does not publish a “Buy Box loss burst” alert. The closest equivalents:
  1. Inventory → Manage Inventory shows the Featured Offer (Buy Box) Price per ASIN. Eyeball your top SKUs against this column.
  2. Pricing → Manage Pricing flags ASINs where you don’t currently hold the Buy Box, with the reason in the Status column.
  3. Reports → Business Reports → Detail Page Sales and Traffic by Child Item shows the Buy Box Percentage per ASIN over time. The async report lags 24 to 48 hours, so it’s NOT a real-time alert source; use this card instead.
Why our number may legitimately differ from anything you’d build manually: Cross-connector reconciliation:

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Known limitations / merchant FAQs

The alert just fired with 5 ASINs. What do I do in the next hour? Open the per-ASIN drill-down and look at three things for each ASIN: (1) competing offer price (Pricing API or Manage Pricing in Seller Central), (2) FBA inventory level and last replenishment date on Days of Cover, (3) any new offer from a non-authorised seller (potential hijacker, see Hijack Risk). The fix paths split: pricing wars need a re-pricing decision (or a Brand Registry violation report); inventory failures need a same-day expedite; hijackers need a Brand Registry takedown request. My burst alert fires every Monday morning. Why? Almost certainly an FBA replenishment cadence issue. Many sellers ship FBA replenishment loads to land Mon to Wed; if a top SKU runs out over the weekend before the load lands, the Buy Box flips to a third-party reseller and the alert fires Mon morning. The fix: increase the safety stock buffer on top SKUs, or shift replenishment cadence to land Fri/Sat. Pair with Days of Cover to identify which SKUs. The alert mentioned commission, but I thought this was about Buy Box. What’s the relationship? The alert itself is purely about Buy Box state, not fees. But the downstream impact compounds: Buy Box loss removes the order from your account, so you also lose the (negative) Amazon referral fee and FBA fee on that order. Net-net you lose roughly 87% of the gross unit revenue (the order goes to the competitor at a similar net margin). Don’t think about fees during burst triage; act first, reconcile later. ACOS, what should my Amazon Ads team do during a burst? Pause campaigns on the affected ASINs immediately. Ads on a non-Buy-Box ASIN burn money because clicks send shoppers to a product page where the “Buy Now” button hands the order to a competitor. Once Buy Box recovers, restart the campaigns; until then, the ad spend is largely wasted. Cross-check on Ad Spend on Out-of-Stock ASINs, the same logic applies. FBA fees question, would lowering FBA fee tier help me hold Buy Box? No, FBA fees don’t directly affect Buy Box allocation; price, Prime-eligibility, fulfilment performance, and seller rating do. The fee question is downstream. If you’re contemplating a smaller-size-tier reclassification to save FBA fee dollars, that’s a margin decision unrelated to Buy Box. See FBA Fees. Multi-marketplace, does the alert fire across UK + DE + FR + IT + ES separately? Yes. Each marketplace has its own Buy Box state per ASIN; the alert evaluates each independently. A burst on amazon.de is a different operational event from a burst on amazon.co.uk; the resellers are different and the fix may be different (some EU resellers operate cross-marketplace, others are country-specific). The drill-down splits by marketplace. Settlement timing, does the burst affect when I get paid? Yes, indirectly. Pending settlements continue to clear on the standard 14-day cycle for orders already placed. But the burst means future orders go to competitors, so future settlements are smaller. The cash impact lags the revenue impact by 14 days both on the way down and on the way back up. See Pending Settlement. Return-window confusion, do return-window issues cause Buy Box bursts? Sometimes, on FBM. If your fulfilment partner is missing the promised handling time, Amazon’s algorithm can mark the listing as poorly-performing and flip Buy Box to a competing reseller with cleaner metrics. Once you’re below the Account Health Late Shipment Rate threshold, this becomes systematic rather than per-ASIN. Pair with Late Shipment Rate and Account Health Status. Why isn’t the Shopify-Amazon channel app a useful tool here? Because the channel app is publishing-only; it has no signal on Buy Box state. Buy Box is governed by SP-API; the channel app cannot detect or remediate Buy Box loss. Use this alert and the underlying Pricing API directly; the channel app is unrelated. Why does today’s alert sometimes mention the same ASIN twice in one day? Because the burst can flip back and forth multiple times within 24 hours during an active reseller pricing war. The alert de-duplicates within the same 24-hour window so you’ll see each ASIN listed once, but if the same ASIN flips again on the next 24-hour boundary the alert can re-fire. If you see persistent flicker on one ASIN over multiple days, that’s a structural pricing war; consider whether to engage on price or escalate the reseller relationship via Brand Registry.

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Tracked live in Vortex IQ Nerve Centre

Buy-Box Loss Burst is one of hundreds of KPI pulses Vortex IQ tracks across Amazon (Selling Partner) 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 or book a demo to see this metric running on your own data.