How Does It Work?
- Install our Free Chrome Extension
- Go to Amazon.com (or any other countries)
- Search for a keyword in the Amazon search bar
You will see the average monthly sales and the estimate for the previous months (if available). Both in terms of revenue and units sold.
Sales by ASIN variation
By going to the page of an ASIN, you will be able to see the units sold for each individual child ASIN (variation). This will help you understand which variation of a competitor is more popular and in which month of the year.
Best-seller rank (BSR) and Sales volume
The Best Seller Rank (BSR) is a ranking index of a product in the list of best-selling products in its category (leaf or root). Every hour, Amazon calculates the sales of all ASINs in the category and ranks them from the highest sold. The top-selling will have position #1. To account for spikes in traffic, promotions, and seasonality, Amazon considers sales generated over multiple time horizons: 6 hours, 24 hours, 7 days, 365 days.
Afterward, a weighted average is calculated, where recent intervals have a greater weight. This is the BSR formula, updated hourly by Amazon.
Average Units Sold = 35% * Units Sold last 6h + 50% * Units Sold last 24 hours + 10% * Units sold last 7 days + 5% * Units sold last 365 days
As you can see, sales from the last year are considered but only have a 5% weight. The last few days have a greater weight, which is why if you have a spike in traffic, you see an immediate effect on the BSR. The average weight is 19 days.
Therefore, BSR and units sold are directly related. Once the average sales for each product in the category are calculated, they are then ordered from highest to lowest, and each ASIN is assigned a ranking index (called Best Seller Rank BSR).