Privacy Policy — Royalty Lens

Last updated: 7 September 2026

Short version: Royalty Lens has no server. It collects nothing, transmits nothing, and shares nothing. Everything it computes stays in your browser on your machine.

What the extension does

Royalty Lens is a browser extension that displays book market research metrics — sales rank, estimated sales and royalties, publisher type, and title analysis — as an overlay on book listing and product pages on amazon.com. All figures are calculated locally in your browser from information that is already publicly visible on those pages.

Information we collect

None. The developer receives no data of any kind. There is no account system, no sign-up, no analytics, no telemetry, no crash reporting, and no backend service to send anything to.

Information stored on your device

The extension keeps the following in your browser's local extension storage. It never leaves your computer, and it is not readable by the developer or by any third party:

Your settings (whether the extension is enabled, print-cost options)
A cache of book details already looked up, expiring after 12 hours
Your library of analysed books and scanned categories
Books you explicitly save

You can erase all of it at any time by clearing the rank cache from the extension popup, or by removing the extension.

Network requests

The extension makes requests only to amazon.com, and only to pages you are already browsing or have explicitly asked it to analyse. These requests come from your own browser session, exactly as if you had opened those pages in a tab yourself. The extension contacts no other server — including none belonging to the developer, because none exists.

Permissions and why they are needed

storage and unlimitedStorage — to keep the settings, cache and library described above on your device. These permissions grant local storage only; they do not enable any network access.
*://*.amazon.com/* — the extension only functions on that site's book pages. It is deliberately scoped to a single domain and cannot read any other website.

Data sharing and sale

We do not sell, transfer, or share user data with anyone, for any purpose. We do not use data to determine creditworthiness or for lending purposes. As no data is collected in the first place, there is nothing to share.

Remote code

The extension executes no remotely-hosted code. All of its scripts are contained in the package you install.

Children's privacy

The extension collects no personal information from anyone, including children under 13.

Changes to this policy

If a future version of the extension ever collects or transmits data, this policy will be updated before that version is published, and the change will be described in the extension's release notes.

Contact

Questions about this policy: reachleoichi@gmail.com