Privacy

This is one page selling one workbook. There is no account, no login and no newsletter you get signed up for without asking.

Who is responsible

What we collect, and why

Your email address, when you buy

Needed to send you the download and to handle a refund if you ask for one. Kept as long as the tax rules require us to keep the sale on file, then deleted.

The payment itself

Sold and delivered by Adsfair B.V.. The price is $9 USD, paid on this site. We never see or store your card number. We see that a payment succeeded, for how much, and the email address attached to it.

Which advert you came from

Adverts add two values to the link you clicked: an anonymous visitor identifier and a zone number identifying the site the advert ran on. We keep those so we can tell which adverts lead to sales and stop paying for the ones that do not. They say nothing about who you are and we cannot turn them back into a person.

How the page was used

Whether the page was opened, whether it was read past the first screen, whether the buy button was clicked, roughly which country the request came from, and the screen width. We use it to decide what to rewrite. It is not linked to your name or your email.

Cookies

Four small cookies, all first-party, none of them shared with an advertising network for profiling:

• the advertising identifier and zone from the link you arrived on, so a purchase can be matched to the advert that paid for it;
• which version of the page you were shown, so it does not change under you;
• your language choice, English or Dutch.

You can delete them at any time in your browser. The page keeps working without them; we just lose the ability to tell which advert did the work.

Who else touches the data

• Adsfair B.V. — processes the payment and issues the invoice.
• Vercel — serves this page and keeps short-lived server logs.
• Our email provider — delivers the download link and the confirmation.
• PropellerAds — receives a signal that a sale happened, with the anonymous visitor identifier and the amount. Not your email, not your name.

We do not sell data, we do not run advertising trackers on this page, and we do not add you to a mailing list because you bought something.

Your rights

You can ask what we hold about you, ask for a copy, ask us to correct it, or ask us to delete it. One email to henkjandekrijger@gmail.com is enough and you will hear back within a few days. If you are not happy with the answer you can complain to the Dutch Data Protection Authority, the Autoriteit Persoonsgegevens.

Last updated 13 September 2026.