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How are sales and unit estimates calculated?
How are sales and unit estimates calculated?

Questions that may arise about the Market Explorer. How are sales and units estimated, when is the data updated, and much more!

Marco Varnas avatar
Written by Marco Varnas
Updated over a year ago

How are sales and units estimated?

We have developed a proprietary algorithm that uses advanced machine-learning models to estimate sales and units as accurately as possible. The model uses among others the Amazon best seller rank (“BSR”), keyword rankings, and reviews.

Sales and units are estimated on weekly basis. Prism shows data on a weekly basis. A week is defined as Sunday-Saturday. New data for the week is loaded into the tool every Tuesday. It is currently not possible to see sales on a daily level.

Sales and units are estimated on parent ASIN level. If an ASIN has multiple variations Prism will show sales and units for all variations combined (i.e. for the parent ASIN). It is currently not possible to see sales and units for individual variations (i.e. child ASIN).

Sales and units are estimated before returns & cancellations. Example: A shopper buys a product on January 1st. The shopper then returns the product to Amazon two weeks later on January 14th. Prism will include that order in the sales estimates for January 1st. Prism does not adjust sales estimates for returns or cancellations.

Sales and units are estimated for the entire ASIN. The numbers displayed in Prism are the total sales for that ASIN, not the sales of an individual Seller or Vendor offering that ASIN. If there are multiple sellers and/or a Vendor selling an ASIN the sales shown in Prism will be the total of all the Sellers and Vendor selling that ASIN.

For Vendors only: Sales and units are the retail sales / sell-out sales. The sales and unit numbers represent the numbers of the units sold to the end-consumer / shopper.

The estimates differ from the actuals that I see for my brand / for my products. Why?

There are different potential reasons that explain differences between the actual data you see (e.g. in Seller Central, the Perpetua “Sales” tab, or the Perpetua “Traffic Reporting” tab) and the data you see in Prism.

  1. You don’t own 100% of the Buybox / you didn’t generate all sales of an ASIN
    Prism estimates all sales for an ASIN, irrespective of who owns the buybox. Your actual reporting will only show you the sales that you generated. If another seller sold the ASIN as well you will not see these sales in your actuals, but they will be included in the Prism estimates.

  2. You don’t sell all ASINs of a brand
    The “Explorer” will show all ASINs of a brand, irrespective of the seller. If another seller is selling an ASIN of the brand and you don’t offer that ASIN your actuals will not include sales from this ASIN while the Explorer will include these sales.

  3. Prism doesn’t estimate all categories
    Prism generates sales estimates for ASINs of the following categories. If a brand has ASINs in categories for which Prism doesn’t generate sales estimates the Explorer will not include these sales while your actuals will.

  4. Prism only shows ASINs with >10 units sold / per year
    The Explorer only includes ASINs that sell at least an estimated 10 units per year. Your actuals also include ASINs that sell <= 10 units/year.

  5. A brand may have multiple spellings

    The Explorer allows you to select only one brand at a time. If a brand has multiple spellings you will see only the ASINs that match exactly that spelling.

  6. Prism estimates on a parent ASIN level
    The Explorer only displays sales estimates on the parent ASIN level. We will multiply the units sold by the parent ASIN with the average price of the parent ASIN for the week. If prices of the child-ASINs differ significantly this can lead to inaccurate sales estimates.

  7. Prism shows estimated sales
    Amazon is not sharing the actual sales numbers for an ASIN. We, therefore, need to estimate sales. While we are working very hard to make as accurate estimates as possible it is impossible to be 100% accurate all the time. You should expect a small difference between the Prism estimates and the actual sales.


Article last updated October 2022. If you find this information to be out of date, please contact hello@perpetua.io.

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