KDP NicheLens

NicheLens Pro helps self-publishers research book niches while they browse Amazon.com. It reads the Amazon page already open in the current tab and turns the visible Best Sellers Rank (BSR) and listing details into practical estimates. Free features - Product-page estimate card: estimated daily sales, monthly sales, and monthly royalty from the page's BSR and price. - Search side panel with up to 20 visible results: title, price, review count, rating, sponsored flag, and saved BSRs for product pages you have visited. - One-click copy of Amazon's own search-box suggestions. - Up to 10 product-page estimates per day; the counter resets at local midnight. - Editable BSR-to-sales table and royalty-rate assumption in Options. Pro — optional $39 one-time license via Gumroad - Unlimited product-page estimates. - Niche score (0–100) for the current search page, using on-page results and BSRs saved by visiting product pages. - CSV export of the side-panel table. - Save up to 200 niches locally in the browser. Install the free extension, open Options, buy a license on Gumroad, and paste the license key to verify it. The extension does not bill through Chrome. The license is checked with Gumroad when you verify it; a stored license is re-checked about every 7 days when the extension UI opens and a check is due. How estimates work NicheLens uses a tiered BSR-to-daily-sales table with editable defaults. Estimated monthly royalty is estimated monthly sales × list price × the royalty-rate setting (70% by default). It does not subtract delivery, printing, or other costs. If Amazon exposes no usable price, NicheLens uses a $4.99 fallback price as the estimate input. All figures are estimates, not Amazon or KDP data, and the fallback is not a purchase price. Privacy and limitations - NicheLens reads only Amazon.com pages you open yourself. It does not crawl, prefetch, or fetch product pages in the background. - Amazon page content stays on the device. No Amazon page data is sent to our servers. - The only network call made by the extension is the optional Gumroad license-verification POST to https://api.gumroad.com/v2/licenses/verify (including the license key and product ID). - No analytics, ads, account system, or remote code. - Works on Amazon.com (US) in this version. - NicheLens Pro is not affiliated with, endorsed by, or sponsored by Amazon.com or Kindle Direct Publishing. Amazon and Kindle are trademarks of Amazon.com, Inc. or its affiliates.