🏪 Buy Box Shares (SM)

Dashboard link: https://app.emax-digital.com/seller-monitoring-standard/buy-box-share-seller-count

Overview

The Buy Box Shares dashboard shows who is winning the "Add to Cart" button on your catalogue ASINs and how crowded the competitive field is around them. For each marketplace it tracks the share of Buy Box wins per seller, the number of competing sellers and offered ASINs over time, the daily spread of offer prices, and an ASIN-level breakdown that estimates how much revenue third-party sellers may be capturing through the Buy Box.

It is built for brand and marketplace managers who need to monitor unauthorised resellers, price erosion, and Buy Box loss — and to quantify the commercial impact when it happens. Use it to decide which sellers to engage with, which ASINs to defend, and where pricing or distribution interventions are needed.

This view is part of the Seller Monitoring dashboard cluster.

What You Can See on This Dashboard

The dashboard is organised in two blocks: a Buy Box & competition overview (share of wins per seller, plus a daily view of competing offers and price spread) and an ASIN-level breakdown that puts a revenue figure on third-party Buy Box ownership.

Section 1 — Buy Box Share per Seller [%]

A pie chart showing how Buy Box ownership is distributed across all sellers competing on your catalogue ASINs within the selected period. Each "slice" represents one seller's count of Buy Box wins — where one win = one ASIN holding the Buy Box on one day.

Key metrics:

• Seller Id — the unique Amazon identifier of the competing seller.

• Seller Name — the public name of that seller on Amazon.

• Buy Box Count — the total number of ASIN-days that seller held the Buy Box during the selected period.

How to read it: A small number of large slices means Buy Box ownership is concentrated (often a healthy sign if you or your authorised distributor are one of those slices). Many small slices means competition is fragmented across resellers — typically a warning sign.

Notes: Only offers with an active listed price and Buy Box winner status are counted. ASINs flagged as "ignored" in your setup are excluded. Results respect the Marketplace, Category, ASIN, Tag, and time-range filters.

Section 2 — Number of Offered ASINs and Sellers (Daily Offer Price Range)

A daily trend chart of the price competition on your catalogue, alongside the volume of competing offers. Despite the section title, this chart actually combines two related views: how many offers exist and what price range they cover.

Key metrics:

• Number of Offers — count of distinct seller-ASIN combinations with an active listed price on that day. A proxy for how crowded the competitive field is.

• Lowest Price — the cheapest active offer recorded that day across all sellers and ASINs. Persistent drops here often signal aggressive undercutting or a seller pricing below your recommended retail price (RRP).

• Highest Price — the most expensive active offer that day. Indicates the upper boundary of the market.

• Average Price — the mean listing price across all active seller-ASIN combinations that day. A central reference for the overall price level.

• Report Date — the day the snapshot refers to.

How to read it: A widening gap between Lowest and Highest Price suggests inconsistent seller pricing — often a sign that resellers are testing the floor. A rising Number of Offers without a matching revenue lift means more sellers are competing for the same demand, which usually erodes margin.

Notes: Price values may be hidden for ASINs where price disclosure is restricted. Only offers with an active listing price are included.

Section 3 — Buy Box Share & Revenue Estimate by ASIN

A detail table that puts a revenue figure on the Buy Box analysis. For each seller–ASIN combination in the selected period, it shows the share of Buy Box days held, the average price at which that seller won the Buy Box, and a lower-bound estimate of the revenue that may have been generated.

Columns shown:

• 📷 — product image.

• ASIN · 🔗 (link to the product detail page) · Product Title Short · SKU · Product Title — product identifiers.

• Seller Name — the seller this row refers to.

• Estimated Min. Revenue Last Month — a lower-bound revenue estimate: Buy Box Percentage × Recent Sales (last 30 days) × Avg. Buy Box Price. Estimates the minimum revenue this seller may have generated from the Buy Box on this ASIN last month.

• Buy Box Percentage — the share of total Buy Box wins this seller held for the ASIN during the selected period.

• RRP (Recommended Retail Price) — your reference price for the ASIN.

• Avg Buy Box Price — average price at which this seller held the Buy Box across the days they won it.

• Avg Offer Price — average price of this seller's offers on days when they did not hold the Buy Box. Useful for understanding their non-winning pricing behaviour.

• Price Diff — the relative difference between the seller's Avg Buy Box Price and their Avg Offer Price. A negative value means they price lower when not winning the Buy Box.

Notes: The revenue estimate is directional, not exact. It depends on Amazon's "Bought in past month" figure on the detail page, which is itself an approximation. Price values may be hidden where price disclosure is restricted.

Available Filters

Filter interaction notes

• Subcategory depends on Category. Selecting one or more Categories narrows the Subcategory dropdown to only sub-categories that belong to those Categories.

• Seller Name filters every chart and the ASIN table on the page — useful to focus the entire dashboard on a single suspected reseller.

• ASIN is single-select. To look at a small group of products, use Tag or Category instead.

• Ignored ASINs (flagged in your catalogue setup) are excluded from all results regardless of filter selection.

Use Cases

1 — Identifying unauthorised resellers

You want to find out who is competing for the Buy Box on your own catalogue.

• Set Marketplace to the market you want to investigate and leave Seller Name empty.

• Open the Buy Box Share per Seller pie chart and identify sellers other than you or your authorised distributors.

• For each unfamiliar seller, set Seller Name = that seller and read the ASIN table to see which ASINs they target, their Buy Box share, and their pricing behaviour.

• The Estimated Min. Revenue Last Month column gives you a defensible number when escalating internally or to legal.

2 — Measuring price erosion over time

You suspect resellers are pushing prices down across your assortment.

• Look at the Daily Offer Price Range chart. Compare Lowest Price today vs. a few weeks ago.

• A consistently falling Lowest Price, especially below your RRP, indicates active undercutting.

• Cross-check the Price Diff column in the ASIN table — sellers with a strongly negative Price Diff are dropping prices specifically to win the Buy Box, then raising them once they have it.

3 — Prioritising ASINs to defend

You can't fix every Buy Box loss at once — you need to pick the ones that matter financially.

• Open the ASIN table and sort by Estimated Min. Revenue Last Month (descending).

• The top rows are the ASIN–seller combinations where third-party Buy Box ownership is costing you the most revenue.

• Use Buy Box Percentage to distinguish between sellers who occasionally win and those who dominate ownership of a given ASIN.

4 — Tracking the impact of an intervention

You've issued a cease-and-desist to a reseller, or fixed a pricing inconsistency with a distributor.

• Filter Seller Name = the seller you targeted, set the time range to span before and after the action.

• Watch the Buy Box Share per Seller chart and Buy Box Percentage in the ASIN table — a drop confirms the action worked.

• If the seller is gone but a new one has appeared in the pie chart, that's a sign the inventory leak hasn't been closed at source.

5 — Monitoring competitive crowding

You want to know how busy the competitive field around your products has become.

• Watch the Number of Offers trend on the daily chart over time.

• A steady rise in Number of Offers, combined with a widening Lowest-vs-Highest price spread, indicates more sellers are entering your catalogue and pricing inconsistently — often a leading indicator of margin pressure.

Limitations & Notes

• Daily snapshot model. Buy Box ownership and offer prices are captured as daily snapshots. Very short-lived Buy Box wins or intra-day price changes between snapshots may not be captured.

• One Buy Box win = one ASIN-day. The Buy Box Count metric reflects the number of ASIN-days a seller held the Buy Box, not the number of sales generated. A seller can hold the Buy Box without making any sales.

• Revenue is an estimate, not a measurement. The "Estimated Min. Revenue Last Month" column relies on Amazon's "Bought in past month" figure, which is itself an approximation rounded to ranges. Use it as a directional minimum and a prioritisation tool, not as an audited revenue figure.

• Price disclosure may be restricted. For some ASINs, price values (Lowest / Highest / Average / Avg Buy Box Price / Avg Offer Price) are hidden in line with Amazon's data-disclosure rules. Buy Box share and offer counts remain available.

• Ignored ASINs are excluded. Any ASINs you have flagged as "ignored" in your catalogue setup do not appear in any chart on this dashboard — including the seller pie chart. Review your ignore list periodically.

• Marketplace filter is single-select. Cross-marketplace comparisons require running the dashboard once per marketplace.

• ASIN filter is single-select. For multi-ASIN investigations, use Tag, Category, or Subcategory to define the scope.

• Seller identity caveat. The same operator can sometimes appear under multiple seller IDs/names. When investigating a specific reseller, scan the seller list for variants of the same name before concluding the issue is resolved.

Data Refresh

Data updates daily.