How these notes are written

Uncertainty

Every unit estimate derived from rank carries wide error, and these notes state it. Ranges appear in the figure rather than in a footnote, because footnoted uncertainty is dropped when a number is quoted onward.

Where a conversion basis is used, its source and date are named. Where no suitable basis exists, the note says so rather than borrowing one from a different category.

Confounders before conclusions

Availability, price, seasonality, market-wide movement and data integrity are checked before any interesting explanation is offered. Several notes are entirely about this discipline, because it is where most published rank analysis fails.

Explicit limits

One note lists the questions this data cannot answer, with alternatives for each. Declining a question well is treated here as part of the method rather than as a failure of it.

Commercial position

No paid reviews. No sponsored content. No paid links. No affiliate arrangements. No guest posts. No product recommendations.

This is stated at length because the previous site at this address sold review placement, and the distinction matters.

Scope limits

Nothing here assists rank manipulation, incentivised or purchased reviews, or circumvention of marketplace rules. The note on services that sell these covers what is being sold, what the enforcement position is, and the practical argument that manipulation destroys a seller's own ability to measure anything.

Where data collection is discussed, the note states plainly that the legal position on automated collection is unsettled, jurisdiction-dependent and a matter for advice rather than for a general guide.