Sales Estimator

Best Seller Rank is the one demand signal Amazon shows publicly. It is not a sales number, but it can be read into a sales range. This skill turns a BSR into an estimate, and a set of BSRs into a market size, with honest confidence bounds.

When to use this

• Estimating how many units a product or competitor sells per month.
• Sizing a niche from the BSRs of its top listings.
• Judging whether demand justifies entering a category.
• Comparing the demand behind two products or two price points.

The framework. The Rank Curve Read

BSR is a rank, not a count. You never convert it with a magic constant. you read it against the sales curve it sits on. The Rank Curve Read is three properties of that curve, and every honest estimate has to respect all three.