Cookies

A cookie is a small file placed on your device by the site you are visiting. We use as few as possible.

Strictly necessary cookies

These make the site work: keeping you signed in, security, and remembering your language choice. They require no consent and are not used for profiling. Your language preference is stored locally in your browser and is not sent to any third party.

Audience measurement

We measure traffic in aggregate to understand which pages are useful. Where this involves a non-essential cookie it is only enabled with your consent, and refusing it has no effect on your use of the site.

Where your visit came from

When you arrive, our own server keeps for 30 days, in a cookie that belongs to letztest.lu (lt_origin) and with no third-party service, the landing page, the site you came from, the date of your first visit and the parameters of the ad or link you followed (utm_source, utm_medium, utm_campaign, utm_content, utm_term, fbclid, gclid), and attaches them to your order so we know which ad led to the purchase.

Advertising and Meta measurement

We run advertising campaigns on Meta platforms (Facebook, Instagram). To see which ads actually bring learners, the site can load the Meta pixel and send the same events from our server through Meta's Conversions API.

None of this loads until you have accepted. On your first visit a banner appears with two buttons of equal weight, "Accept all" and "Only necessary", and a link to this page. Until you accept, Meta's script is not downloaded and no event is sent.

If you accept, the events measured are: a page being viewed (PageView), starting a payment (InitiateCheckout, with the amount) and a confirmed purchase (Purchase, with the amount). Each event carries a unique identifier shared between your browser and our server, for one purpose only: so that Meta does not count the same event twice. What our server sends includes your IP address, your user agent, the advertising identifiers Meta has set in your browser, and, for a purchase, your email address as an irreversible hash.

Your choice is kept for twelve months in a strictly functional cookie (lt_consent). You can change it at any time through the "Change my cookies" link in the footer of every page: the banner comes back, and refusing stops the measurement immediately.

Managing cookies

Your browser lets you block or delete cookies already stored. Blocking strictly necessary cookies may prevent you from signing in.