Data sources

Observed from Amazon's public pages

Prices, ratings, review counts, Best Sellers Rank, category ranks, descriptions and listing details come from Amazon's public product and search pages. Each value is as of the time shown.

Estimated

• Sales and revenue are estimated from Best Sellers Rank. They are approximate and usually shown as a range: use them to compare books, not as exact sales figures.
• Monthly keyword search volume is an approximate estimate. When no volume figure exists for a keyword, the tool shows an estimated demand level (High, Medium or Low), worked out by comparing it with keywords of the same search whose volume is known. Hover a level to see whether it comes from a figure or is an estimate.
• In Reverse ASIN, when few ranking keywords are known for a book, keywords are added from the book's own title and Amazon's search suggestions. They carry a relevance level and no rank, because the book was not seen ranking for them.
• Sub-niche ideas in Category Insights are suggestions drawn from the titles of the category's best sellers, not measurements.

Calculated by us

• Demand, Competition and Opportunity scores use published formulas shown in the tool, based on the observed numbers above.
• Category figures come from the books BookIntel has recorded in each category. Nothing is filled in for categories without records.
• Trends and history start on the first day BookIntel recorded a keyword, book or category. We never invent earlier history.

Public registers

Trademark results come from the United States Patent and Trademark Office public register and are shown as that register states them.

When data is missing

If a source cannot give us a value, the tool shows a dash, says so, or shows a level that is labelled as an estimate. We never present an estimate as a measured number.