At a glance
Cross-channel revenue split between eBay GMV and Amazon sales over the 90-day window. The “where is my marketplace volume going” donut, telling the seller whether they’re an eBay-first, Amazon-first, or balanced multi-marketplace operator, and how that mix is shifting.
| What it counts | eBay_GMV / (eBay_GMV + Amazon_sales) × 100 and the inverse, both shown on the donut. eBay side uses pricingSummary.total.value from the Sell Fulfillment API; Amazon side uses Order Reports from SP-API. |
| Listing-format scope | All eBay formats (fixed-price, auction, Best-Offer-resolved). Amazon side includes both FBA and FBM (seller-fulfilled) orders. |
| GMV / fees framing | Gross of fees on both sides. eBay side is gross of FVF; Amazon side is gross of referral fees. For an apples-to-apples comparison this is the right framing because both marketplaces report this way natively. |
| Promoted Listings | Both promoted and organic orders contribute identically on both sides. The card doesn’t separate paid-placement revenue. |
| Multi-site aggregation | The card pairs each connected eBay marketplaceId with the corresponding Amazon marketplace by default (eBay UK paired with Amazon UK, eBay US paired with Amazon US). Per-pair share is shown on expansion. |
| Currency | Per-marketplace native currency, summed without FX. UK + US sellers see arithmetic-summed totals; for board reporting do the FX manually. |
| Best-Offer-resolved orders | Counted on the eBay side at the negotiated total. |
| Refunds | Both sides are gross of refunds. For a net-of-refund view, subtract refund value from each side manually. |
| Cancellations | Buyer-cancelled-pre-payment orders are excluded by both APIs. Seller-cancelled post-payment cancellations are typically included until refund processing completes. |
| Time window | 90D (rolling). The 90-day window is long enough to smooth seasonal noise and short enough to capture meaningful share trends. |
| Alert trigger | - |
| Roles | owner, finance |
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 home-and-garden seller running ebay.co.uk + amazon.co.uk, with US expansion launched 6 months ago via ebay.com + amazon.com. 90-day window: 02 Feb 26 to 01 May 26.| Channel | 90D GMV / sales | Share |
|---|---|---|
| ebay.co.uk | £318,000 | 36.1% |
| amazon.co.uk | £404,000 | 45.9% |
| ebay.com | $52,000 | 5.9% (in £, ~£41,000) |
| amazon.com | $148,000 | 12.1% (in £, ~£117,000) |
| Total | £880,000 (FX-adjusted) | 100% |
| eBay total share | 42.0% | |
| Amazon total share | 58.0% |
- The seller is Amazon-first overall (58% Amazon vs 42% eBay). This is typical for UK home-and-garden sellers; Amazon’s Prime delivery promise dominates impulse / replacement purchases in this category. eBay’s stronger position is in collectibles, vintage, and refurbished, none of which are this seller’s lines.
- The UK market is more eBay-friendly than the US. UK split is 44% eBay / 56% Amazon; US split is 33% eBay / 67% Amazon. The US market consolidation toward Amazon is structural; eBay UK has held more ground because of legacy buyer behaviour and stronger collectibles share.
- Trend line over 4 quarters typically shows Amazon gaining 1 to 2 ppt per quarter. This isn’t a brand-specific trend; it’s an industry pattern. Sellers planning marketplace strategy should assume Amazon share continues to grow over the next 24 months unless they actively invest in eBay-specific levers (Promoted Standard, eBay Stores subscription, Best Offer dynamics).
- The TRS-discount on eBay matters for share economics. A seller losing TRS sees eBay net margin fall by ~1.3 percentage points (the lost FVF discount). At 42% eBay share, that’s a ~0.5% drag on overall blended margin, real but not alarming. A non-TRS Amazon-first seller might rationally migrate even more share to Amazon.
- Currency aggregation muddies the headline. The FX-adjusted £880k total uses today’s USD/GBP rate (~£0.79/$). Over the 90-day window the FX rate moved ~3%, so the historical-FX-adjusted total may differ from the spot-FX-adjusted total by 1 to 2%. For board reporting, agree the FX convention with finance.
Sibling cards merchants should reference together
| Card | Why pair it with eBay vs Amazon Revenue Share |
|---|---|
| eBay Total Revenue | The eBay side of the comparison. |
| Amazon Total Sales | The Amazon side of the comparison. |
| Catalogue Drift vs Amazon | Pricing-side cross-channel context. Drift on individual SKUs explains share movements at the catalogue level. |
| Amazon Top SKUs Missing on eBay | The “untapped channel-expansion” view. Adding velocity-proven Amazon SKUs to eBay shifts share toward eBay. |
| Marketplace Fees | eBay fee math. Compare against Amazon referral fees for net-margin parity. |
| Promoted Spend | eBay-side ad investment that drives share. |
| Shopify Total Revenue | Triangulation: marketplace share doesn’t include the seller’s own DTC channel. For full revenue mix, add Shopify alongside. |
| Health Score | eBay-side operational health affects share migration; degraded health pushes volume toward Amazon. |
Reconciling against the vendor’s own dashboard
Where to look in eBay Seller Hub (eBay-side data):Seller Hub → Performance → Sales, eBay GMV for the period.Where to look in Amazon Seller Central (Amazon-side data):
Amazon Seller Central → Reports → Business Reports → Sales and Traffic. Amazon ordered-product sales for the period.Sum each side’s 90-day total and compute the share manually; the figure should match this card to within a small reconciliation gap. Timing, settlement, and reporting-lag table:
| Topic | Detail |
|---|---|
| Timezone | eBay GMV uses UTC for period boundaries (Pacific Time at source). Amazon orders use Pacific Time (US accounts). The card normalises both to UTC; small (sub-day) boundary effects average out over 90D. |
| Settlement / payout impact | The card uses gross GMV / sales, not settled-cash. Different channels have different settlement cadences (eBay TRS near-instant, Amazon 14-day rolling). Cash-flow share differs from revenue share by 0 to 5 ppt depending on payout timing. |
| Promoted Listings cost reporting lag | Not directly relevant; both sides are gross of ad fees. |
| API throttling | eBay Sell Fulfillment API: 5,000 calls/day. Amazon SP-API Order Reports: per-marketplace per-second limits. Full 90-day backfill completes in 2 to 4 hours; the card refreshes daily. |
| Data sync cadence | Both connectors push order events via webhook (eBay) and polling (Amazon). Amazon’s polling cadence is 15 minutes; eBay’s webhooks are 30 to 90 second push. “Today” share is approximate; yesterday and earlier are fully caught up. |
| Reason | Direction | Why |
|---|---|---|
| FX / currency aggregation | Either | Multi-marketplace sellers see arithmetic-summed values without FX in the headline by default. Per-marketplace breakdown gives accurate per-currency comparisons. |
| Refund treatment | Same on both | Both sides are gross of refunds; refund-net comparisons require manual adjustment. |
| Marketplace pairing | Default vs custom | The card pairs eBay-UK with Amazon-UK by default. Custom pairings (eBay-UK with Amazon-DE) are configurable but skew the share interpretation. |
| Time-zone boundary | Within ±1 day | eBay and Amazon use different default timezones; the card normalises to UTC. Small boundary effects on the very first / last day of the 90D window. |
| Card | Expected relationship | What causes legitimate divergence |
|---|---|---|
shopify.total_revenue | Cross-channel triangulation. The marketplace share doesn’t include the seller’s own Shopify storefront. For full revenue mix add Shopify alongside. | Shopify is a separate population; treat as a third pie slice in the seller’s total revenue. |
amazon.total_sales | The Amazon side of this card. Should reconcile 1-to-1. | Identical data source; any divergence is a sync-lag artefact. |
Known limitations / merchant FAQs
What’s a “healthy” share split? There’s no universal answer; depends on category. Apparel, footwear, fashion accessories: Amazon dominant (60 to 80% Amazon share is typical). Collectibles, vintage, refurbished electronics: eBay dominant (60 to 80% eBay share). Home and garden, consumer electronics: Amazon-leaning (55 to 70% Amazon). Industrial / B2B parts: eBay-leaning (45 to 60% eBay) because of long-tail discoverability. Why is my Amazon share growing every quarter? Industry pattern. Amazon’s Prime delivery promise, larger advertising surface, and superior search result quality continue to take marketplace share from eBay industry-wide. Sellers can resist this with eBay-specific levers (Promoted, Best Offer, eBay Stores subscription, TRS-targeted operations) but the structural drift is toward Amazon. Are FBA and FBM split shown separately on the Amazon side? Not on this card. The aggregate Amazon-share figure includes both FBA (Amazon-fulfilled) and FBM (seller-fulfilled). For the FBA / FBM breakdown, see Amazon-side cards. The split matters for fulfilment cost analysis but not for top-line marketplace share. My multi-site numbers: how should I read this for board reporting? The headline shares are FX-aggregated; per-pair (eBay-UK with Amazon-UK, eBay-US with Amazon-US) drilldowns are exact in native currency. For board reporting, agree on either: (a) FX-converted single-currency total share, or (b) per-marketplace-pair share table. The card supports both; default is FX-converted single-currency. Does Best Offer affect my eBay share? Slightly downward. Best-Offer-resolved orders book at the negotiated total (typically 8 to 12% under asking), so a seller with heavy Best Offer activity has slightly lower booked GMV than a seller with the same volume of BIN orders. Effect is small (under 1 ppt of share for most sellers). Does Promoted Listings ROI affect this card? Only via volume. Higher Promoted ROI on eBay drives more eBay GMV, increasing eBay’s share. The card itself doesn’t differentiate paid from organic. Why doesn’t Shopify appear here? Because it’s a marketplace-vs-marketplace card, focused on eBay vs Amazon. Shopify is a DTC channel; treat it as a third pie slice when looking at total revenue mix. Some Vortex IQ workspaces enable a 3-channel donut (eBay + Amazon + Shopify); toggle in card settings. My Amazon side dropped 30% but eBay stayed flat, what happened? Three usual causes: (1) Amazon listing suspension or Buy Box loss; (2) FBA inventory stockout (Amazon orders stop, but eBay’s seller-fulfilled inventory keeps shipping); (3) Amazon advertising budget exhaustion. Investigate Amazon-side cards first; the share movement is the symptom, not the cause. Is there an alert on this card? Default: no alert. Some workspaces set a custom alert at “share shifts >5 ppt vs prior 90D” to catch step-changes. Configure in card settings if you want share-trend monitoring. Action playbook for using this card:- Read the headline share monthly to track marketplace mix trend.
- If eBay share is degrading, audit eBay-side operational health (TRS, defect rate) and listing quality (specifics, photos).
- If Amazon share is degrading, audit Buy Box position, FBA inventory levels, and Amazon advertising.
- For multi-marketplace expansion decisions, use this card to identify under-developed channel pairs (e.g. ebay.com share well below ebay.co.uk share = US-eBay underdeveloped, opportunity).
- Pair with Catalogue Drift and Amazon Top SKUs Missing on eBay for the listing-level levers.