Privacy policy

Last updated : 8 August 2026

Merkatiko SRL (Pegasuslaan 5, 1831 Machelen, Belgique, BE 0744.730.564) is the controller of the data collected through centastra.com, in compliance with the GDPR.

Birth data

The date, time and place of birth entered are used solely to calculate and compose the book. They are kept for the time needed for production and any reprint, then erased after the 30-day reprint window. The "next appointment" preview calculates on the fly, without storage.

Order and delivery

The data needed for the order (email, delivery address, dedication) is processed to perform the contract and kept for the legal accounting period. Payment is handled by Stripe; we store no banking data. The book is printed and shipped to order by our print provider (the Lulu network), which receives, for that sole purpose, the name, delivery address and personalised content of the book.

Email and marketing

With your consent (double opt-in), your email may be used to send you a preview of the book and then information about the product. You can unsubscribe at any time in one click. Transactional and marketing sending is operated via Brevo (a European Union company).

Astro alerts

If you turn on the astro alerts (a separate, confirmed opt-in, distinct from the newsletter), we calculate astral positions from your birth (the Sun, the lunar nodes and slow planets) and keep them, together with your email and language, at Brevo (a European Union company), in order to send you personalised messages about the month's sky and major transits. For this service we do not keep your raw date, time or place of birth, only these calculated positions. Consent to the astro alerts is independent from marketing consent: you can withdraw one without affecting the other. You unsubscribe in one click from every email; on unsubscribe, these positions are erased and your address is removed from the list. Sends are logged in a strictly technical way (a contact identifier, without email or birth data), so you are never written to twice.

Reviews

Invitations to leave a review are sent after purchase via Trustpilot, an independent third party that collects and verifies reviews.

Your rights

You have the right of access, rectification, erasure, restriction, objection and portability. To exercise them, use our contact form.

Recipients and processors

Your data is shared only with our processors, solely for the purposes above: Stripe (payment), Lulu (printing and shipping), Brevo (emails, an EU company), Supabase (order storage, EU hosting), Vercel (site hosting), Trustpilot (verified reviews), Google (audience measurement via Analytics 4) and Meta (Facebook and Instagram: measuring our ads via the pixel and the Conversions API; your email (hashed), your IP address and your browser are then shared for matching, only with your consent). Some providers are based outside the EU: any transfer is covered by appropriate safeguards (standard contractual clauses).