Privacy Policy

Last updated: 9 June 2026

KDP Metric is a browser extension for researching Amazon book listings. It is built to be private by default. This policy explains exactly what it does and does not collect, and sets out your rights under the UK GDPR and EU GDPR.

Who we are (data controller)

KDP Metric is an independent project operated by a sole trader based in the United Kingdom. For any privacy question or request, contact us at support@kdpmetric.com. For the purposes of UK and EU data protection law, the operator of KDP Metric is the data controller for the limited personal data described below.

What the extension reads

KDP Metric only reads the content of Amazon pages you deliberately open in your own browser. It does not crawl, open tabs on your behalf, follow links, or make background requests to Amazon. Analysis runs locally in your browser.

What we store on your device

Only your settings (theme, toggles, filters, licence state, and any books you choose to track) are saved locally via the browser's storage. We do not store your browsing history. Extracted listing data lives only in the current view and is discarded when you navigate away.

On-device AI features

Some optional Pro features (such as "KDP Metric AI" / Category Scout) use artificial-intelligence capabilities built into your web browser and provided by your browser vendor (for example, the on-device AI in Google Chrome). When you use these features, the relevant book and page information is processed locally on your own device by the browser's AI. We do not send that information to our servers, and we do not receive your prompts, the AI's responses, or the book data they are based on.

Because this capability is part of your browser, your use of it may also be governed by your browser vendor's own terms and privacy policy, which are between you and that vendor. We do not control the browser's AI and cannot guarantee its availability.

Payments & licensing (Pro)

If you buy KDP Metric Pro, the payment is processed by our reseller and Merchant of Record, Polar. To take payment and issue your licence, Polar collects the personal data it needs — such as your name, email address, billing details and country — under its own privacy policy, as an independent controller of that data. We do not see or store your full payment-card details.

We receive only limited order and licence information (for example, a licence key and its activation status) needed to provide Pro and support it. Your licence key is stored locally on your device so the extension can confirm your access; validating or activating a key sends only the key to the licensing service, never your book data or browsing.

Optional anonymous data contribution

You may choose to turn on "Contribute anonymous data." This is off by default. When enabled, the extension sends only public, factual product data from book pages you view:

• ASIN (Amazon's public product identifier)
• Marketplace (e.g. amazon.co.uk)
• Best Sellers Rank, price, rating, review count, format
• A timestamp

This data describes books, not people. It is aggregated to build shared rank and price trends that benefit all users. We do not ask for or attach your name, email, or account, and we do not build a browsing profile. We do not use this data to identify you, and we do not combine it with any other information to single you out.

Like all internet services, our server may briefly receive the network (IP) address your request comes from as a technical necessity of delivering data. We do not use this to identify you and do not retain it in association with your contributed data. Where any such transient technical data is logged, it is kept only briefly for security and then discarded (see Retention). You can turn the contribution off at any time in the extension's popup.

Anonymous error reports

To keep the tool working when Amazon changes its website, the extension automatically sends a small, anonymous error report only when it detects that its own page-reading has failed (for example, the page clearly has results but our code could read none). The report payload contains only: the extension's parser version, the type of page (search, list or product), the Amazon marketplace (e.g. amazon.co.uk), and a short error code. It contains no web address, no search terms and no book data, and it is not linked to you.

As with any internet request, our server may briefly receive the network (IP) address needed to receive the report. We do not use it to identify you and do not retain it in association with the report. We use error reports solely to be alerted that the parser needs updating.

Feedback you send

If you use the in-app "Send feedback" form, we receive only the message you type. The form does not ask for your email or any contact details, so feedback is anonymous and we cannot reply to it. Please don't include personal information in your message.

Legal basis for processing (UK/EU GDPR)

• Pro licensing and support — processed because it is necessary to perform our contract with you, namely to activate, validate, maintain and support your Pro licence.
• Optional data contribution — processed on the basis of your consent, given by switching the feature on. You may withdraw consent at any time by switching it off; this does not affect data already aggregated and anonymised.
• Feedback messages — processed on our legitimate interest in improving the product. The form collects no contact details.
• Security, reliability and abuse prevention — processed on our legitimate interests in protecting KDP Metric, preventing licence abuse, fraud, misuse and service disruption, and keeping the extension reliable when third-party websites change.

Data retention

• Feedback messages — kept no longer than 30 days, then deleted.
• Contributed book data — retained as aggregated trend history. As it does not identify you, it is not held "about" you.
• Transient technical/security logs (if any) — kept no longer than 30 days, then deleted.

Your rights

Under the UK GDPR and EU GDPR you have the right to access, correct, delete, restrict, or object to the processing of your personal data, and the right to data portability. We hold very little personal data — we do not collect your name, email or account. To exercise any right, email support@kdpmetric.com and we will respond within one month.

If you are in the UK, you may also complain to the Information Commissioner's Office (ICO) at ico.org.uk. If you are in the EU, you may complain to your national data protection authority.

International transfers

Our infrastructure may process requests on servers located outside your country, including outside the UK and EEA. Where any limited personal data is transferred internationally, we rely on appropriate safeguards recognised under UK/EU data protection law, such as adequacy regulations, the UK International Data Transfer Agreement/Addendum, EU Standard Contractual Clauses, or equivalent safeguards where required.

Cookies & tracking

This website uses no cookies, no Google Analytics, no advertising pixels, and no third-party trackers. The extension itself uses your browser's local storage only where necessary to remember your own settings and licence state — never for tracking.

We may use Google Search Console to understand how our website appears in Google Search. Search Console does not place tracking cookies on visitors' devices through our website.

What we never do

• We never sell or rent your data to anyone.
• We never use third-party trackers, advertising, or analytics.
• We never access your Amazon account, cookies, or credentials.
• We never build a profile of your browsing.

Third parties

Contributed data is sent to our own server only. We do not sell or share it with third parties. We use reputable infrastructure providers to host and deliver the service, who process data only on our instructions.

Two third parties act as independent controllers of any personal data you give them directly: Polar, which processes Pro payments and licensing (see "Payments & licensing" above), and your browser vendor, whose on-device AI powers the optional AI features (see "On-device AI features" above). Their handling of your data is governed by their own privacy policies.

Changes to this policy

If we change how we handle data, we will update this page and the "last updated" date above. Material changes affecting personal data will be made clear.

Contact

Questions about this policy? Contact us at support@kdpmetric.com.