Amazon UK Top SKUs Missing on OnBuy, OnBuy

Metrics type: Cross-Platform Metrics • Category: Marketplace

Velocity-proven SKUs that aren’t even listed on OnBuy, the cheapest revenue lift available.

At a glance

Count of the merchant’s Amazon UK top-50-by-revenue SKUs (rolling 30 days) that are NOT currently listed as status = active on OnBuy. Velocity-proven products with a known UK demand signal that the merchant has simply never listed on OnBuy. The cheapest revenue lift available; usually the highest-ROI single recommendation in the AI OS for a merchant running both channels.


What it counts	A scalar count: `COUNT(amazon.top_50_skus_by_30d_revenue NOT IN onbuy.listings WHERE status = 'active')`. SKUs are matched on barcode (EAN, UPC, ASIN cross-reference) first and seller-SKU second; if neither matches, the SKU is treated as missing.
Source data	Amazon SP-API `Reports/GET_SALES_AND_TRAFFIC_BY_ASIN` for the velocity ranking, joined to OnBuy `GET /v2/listings` for the active-listings catalogue. Both sides are filtered to UK marketplace.
Match key precedence	(1) GTIN / EAN / UPC where both sides expose a barcode, (2) seller_sku where the merchant uses identical SKU codes across both channels, (3) ASIN-to-OnBuy listing-id mapping where the merchant has manually populated `external_asin` on OnBuy.
Why “top 50”?	Top 50 by 30D revenue captures roughly 70 to 90% of any merchant’s marketplace volume regardless of catalogue size; lower-velocity tail SKUs are excluded because the listing effort outweighs the revenue lift.
Velocity floor	A SKU must have generated at least £100 of Amazon UK revenue in the trailing 30 days to count as “top”. Lower-velocity SKUs are excluded even if they sit in the top 50 by accident (e.g. a small catalogue).
Currency	Amazon side is GBP-filtered (UK marketplace `A1F83G8C2ARO7P` only). OnBuy is GBP-only by design. No FX conversion.
Refunds / cancellations	Velocity ranking on the Amazon side is gross (matches `amazon_total_revenue` definition); cancellations are excluded from both sides for consistency.
Time window	`30D` rolling. Long enough that one promo week does not skew the velocity ranking; short enough that seasonal SKU cycles surface.
Alert trigger	`>5 top-velocity SKUs missing`. The integer threshold reflects merchant-actionability: 5 missing SKUs is a single afternoon’s listing work; 20+ is a structural under-investment.
Roles	owner, marketing. Action is “list these SKUs on OnBuy” so it sits with whoever owns marketplace expansion.
Only when	`has_amazon_sibling = true`. The card is hidden if the merchant has not connected Amazon (no velocity signal to anchor the comparison).

Calculation

Calculated automatically from your OnBuy 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 small UK kitchen-and-tableware seller, snapshot taken 27 Apr 26. The seller has 220 SKUs total in their Shopify catalogue, 180 listed on Amazon UK, and 95 listed on OnBuy. Their Amazon UK top-50 SKUs by 30D revenue are pulled into the velocity ranking; the engine then checks each one against active OnBuy listings.

Top SKU (anonymised)	Amazon 30D rev	Match key	On OnBuy?
KT-2104 (oak chopping board, large)	£980	EAN matched	Yes
KT-2118 (linen tea-towel set)	£840	EAN matched	Yes
KT-3201 (ceramic mug, navy)	£760	EAN matched	No
KT-3215 (espresso cups, set of 4)	£710	EAN matched	No
KT-2450 (cast-iron skillet, 26cm)	£690	EAN matched	Yes
KT-3210 (ceramic mug, sage)	£620	EAN matched	No
KT-2202 (wooden serving platter)	£580	EAN matched	Yes
KT-3224 (cereal bowl, set of 4)	£540	EAN matched	No
(… 42 more rows …)

Top 50 Amazon UK SKUs (30D)        50
Already listed on OnBuy (active)   42
Missing on OnBuy                    8

What it means for this seller. 8 missing top-velocity SKUs is above the alert threshold of 5. The pattern is clear: the ceramic mugs and bowls (4 of the 8 missing) are a single product category the merchant has not yet rolled onto OnBuy. The lift is mechanical and small-effort:

Action	Effort	Expected lift
List the 8 missing SKUs on OnBuy with same images and titles as Amazon	1 afternoon (~£0 cost)	£180 to £450 / month incremental

Maths: each missing SKU is doing ~£540 to £760 / month on Amazon. OnBuy traffic for the merchant is roughly 10% of Amazon today (see onbuy_xc_share_of_uk_revenue), so the realistic OnBuy lift per missing SKU is £55 to £75 / month. 8 SKUs gives £440 to £600 / month at run-rate, with no incremental ad spend, no inventory cost, and no warehouse change. The cheapest revenue lift available, exactly as the card promises.

Sibling cards merchants should reference together

This card is the entry-point to a “list missing SKUs on OnBuy” workflow. The natural pairings:

Card	Why it matters next to the missing SKU count	What the combination tells you
OnBuy Total Revenue	The current OnBuy baseline.	Lets you size the % uplift the missing SKUs would represent against current OnBuy revenue.
Amazon UK Total Revenue	The velocity-source channel.	If Amazon revenue is dropping, the velocity ranking is shifting; the missing SKUs on this card may be different next month.
Catalogue Drift vs Amazon UK	The “already listed” half of the comparison.	This card flags listings that exist on both channels but with diverging prices or titles. Read together to see (a) what to add and (b) what to fix on what is already listed.
OnBuy Share of UK Revenue	Portfolio context.	If OnBuy share is below 10%, missing SKUs are usually the dominant cause; the lift here is the lever to pull.
OnBuy Active Listings	The denominator.	Shows total OnBuy listings vs total Amazon listings so you can see whether the gap is “8 SKUs” or “the merchant just hasn’t onboarded the catalogue”.
Listings Missing RRP	Adjacent listing-quality issue.	When listing the 8 missing SKUs, set RRP at the same time, or they will be invisible to the “Save X%” badge that drives 15 to 30% of OnBuy click-through.
Top Listings by Revenue	OnBuy-side winners.	Compare against Amazon top-velocity to see whether OnBuy buyers want the same SKUs Amazon buyers do (usually yes for utility, no for impulse).
eBay Top SKUs Missing on OnBuy	The eBay-source twin of this card.	If both Amazon and eBay top-SKUs are missing on OnBuy, the gap is structural (whole catalogue not rolled out); if only Amazon’s are missing, the gap is category-specific.

Reconciling against the vendor’s own dashboard

Where to look in OnBuy’s own dashboard: OnBuy does not provide a “missing-from-catalogue” view because the cross-platform data does not live in the OnBuy console. The closest manual workflow is:

OnBuy Seller Console (https://seller.onbuy.com) -> Listings -> All Listings (export to CSV) Amazon Seller Central -> Reports -> Business Reports -> Detail Page Sales and Traffic by ASIN (export to CSV, filter to UK marketplace, sort by 30D revenue, take top 50) Compare the two CSVs in Excel by EAN or SKU.

The merchant has to do this manually, channel-by-channel, on a frequency they choose. Vortex IQ does it automatically every 24 hours and only surfaces the count above the velocity threshold. Why our number may legitimately differ from a manual sum:

Reason	Direction	Why
Match key precedence	Either	A merchant doing this manually usually matches on SKU code, which fails when the merchant uses different SKU conventions per channel. We try EAN/UPC first, which is more robust.
Velocity floor	Ours lower	Our count excludes SKUs below £100 / 30D Amazon revenue, even if they are in the top 50 (in a small catalogue, the top 50 may include low-velocity tail). A manual top-50 export will not apply this floor.
30D window definition	Marginal	Our window is rolling-30-days ending today (UTC); Amazon Seller Central typically defaults to a calendar-30 window (1st of last month to today). For a 30-day window the gap is small but for a snapshot taken on the 1st of the month it can shift the top 50 by 2 to 5 SKUs.
OnBuy listing status filter	Ours stricter	We require `status = active` on OnBuy. Listings in `pending`, `paused`, or `suspended` are counted as “missing” because they are not buyable. A manual export of “all listings” will not apply this filter and will show the SKU as “listed” when it is actually unavailable.
Variant handling	Either	Amazon ASINs and OnBuy SKUs do not always have the same variant granularity. A “T-shirt, navy, large” might be a single ASIN on Amazon (parent + 18 child variants) but four separate listings on OnBuy. Our matcher normalises to barcode level when possible, but in some categories the variant tree shape genuinely differs.
New SKUs	Ours lower for “this week”	A SKU that started selling on Amazon 4 days ago will not yet be in any 30D top-50 ranking. Our card lags the curve by ~2 weeks after a new SKU enters the velocity tail.

Internal identity:

onbuy_xc_missing_on_onbuy = COUNT(amazon.top_50_skus_by_30d_revenue WHERE NOT EXISTS (onbuy.listing.barcode = amazon.asin.barcode AND onbuy.listing.status = 'active'))

The card has no direct OnBuy or Amazon-side reconciliation; the integrity check is “does the count match a manual diff of the two exports”, which agencies sometimes run quarterly as an audit.

Known limitations / merchant FAQs

Why does this only use Amazon UK as the velocity source, not eBay or my own DTC site? Amazon UK is the largest velocity signal available for most UK brands; it captures price-sensitive demand at scale. eBay UK is the second-best signal but its top-50 is heavily skewed by auction-format and used-goods listings that do not generalise to OnBuy. DTC velocity is sometimes brand-loyal rather than category-demand, so a top-DTC SKU is not always a top-marketplace SKU. We surface eBay-source variants under ebay_xc_missing_on_onbuy for merchants where Amazon is not connected. My count says 12 missing but I just listed all of them last week. Why is it still 12? Two likely causes. First, our refresh runs every 24 hours, so a listing added today appears in tomorrow’s count. Second, the listings may be in pending status while OnBuy reviews them (typical for new categories or new sellers). We require status = active; pending listings count as missing until they go live. If the count has not dropped after 72 hours, the third possibility is a barcode-mismatch on the listings (the merchant entered the EAN incorrectly and our matcher cannot tie the two sides together). Can I get a list of which SKUs are missing, not just the count? The KPI card shows the count; clicking through opens the drill-down view in Nerve Centre with the full SKU list, Amazon revenue, image, and a “Create OnBuy listing” button that pre-fills the OnBuy listing form via OnBuy’s Bulk Listings API. The KPI card alone does not surface the SKU list because for very large catalogues the count is what triggers the alert. What if my Amazon top-50 has SKUs I deliberately do not want on OnBuy (e.g. private-label exclusive)? You can mark SKUs as “Amazon-exclusive” in the Vortex Mind catalogue settings; those SKUs are excluded from the missing-on-OnBuy comparison. The exclusion is per-SKU and persists until you remove it. Use this for FBA-exclusive SKUs, restricted brand-registry items, and SKUs that genuinely do not fit OnBuy’s category mix (e.g. very heavy items where OnBuy’s shipping economics do not work). Why is the threshold 5 missing SKUs, not 1 or 10? 5 reflects the typical action-effort trade-off for a small UK seller. Below 5 the manual listing effort barely justifies the engineering attention; above 5 the merchant is leaving meaningful revenue on the table. The threshold is configurable per-merchant in the manifest if the seller is unusually catalogue-conservative or has a much larger Amazon catalogue. My catalogue is 5,000 SKUs, why does this only look at the top 50? Velocity is power-law distributed; top-50 captures roughly 70 to 90% of marketplace revenue regardless of catalogue size. A “missing-from-OnBuy” view of the full 5,000-SKU catalogue would surface 4,800 missing items, none of them actionable. The top-50 cut concentrates attention on SKUs where listing effort meets demonstrated demand. What if my barcodes don’t match across Amazon and OnBuy? Then the matcher falls back to seller-SKU. If neither matches, the SKU is treated as “missing” even if it is actually listed under a different code. This is a known edge case; the fix is to populate external_asin on the OnBuy listing (OnBuy supports a manual ASIN cross-reference field that the matcher will pick up). Does this count Amazon FBA or FBM separately? No. The velocity ranking is on Amazon UK total revenue regardless of fulfilment method. The OnBuy side is OnBuy-fulfilled-by-merchant only (OnBuy does not run a fulfilment service equivalent to FBA). If a merchant runs FBA-only on Amazon, the missing SKUs flagged here would need to be fulfilled from the merchant’s own warehouse for OnBuy.

Tracked live in Vortex IQ Nerve Centre

Amazon UK Top SKUs Missing on OnBuy is one of hundreds of KPI pulses Vortex IQ tracks across OnBuy 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.

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The AI OS

Amazon UK Top SKUs Missing on OnBuy, OnBuy

At a glance

Calculation

Worked example

Sibling cards merchants should reference together

Reconciling against the vendor’s own dashboard

Known limitations / merchant FAQs

Tracked live in Vortex IQ Nerve Centre

​At a glance

​Calculation

​Worked example

​Sibling cards merchants should reference together

​Reconciling against the vendor’s own dashboard

​Known limitations / merchant FAQs

​Tracked live in Vortex IQ Nerve Centre

At a glance

Calculation

Worked example

Sibling cards merchants should reference together

Reconciling against the vendor’s own dashboard

Known limitations / merchant FAQs

Tracked live in Vortex IQ Nerve Centre