Legal
Privacy policy
In short
- No cookies and no tracking scripts; visitor statistics are anonymous.
- What you send through the contact form or a demo request is used only to answer you.
- I keep requests for at most six months and server logs for at most thirty days.
- I never sell your data and share it only with the processors needed to run the site.
- You can ask for access, correction or deletion at any time: info@atherium.nl.
- If I emailed your business: what data I used and how to opt out.
- If I emailed your garage about online booking: what data I used and how to opt out.
On this page
Who I am
Atherium builds apps, web apps and websites for businesses in the Netherlands, from Amsterdam. Atherium is the controller for the data you leave on this site. Atherium, Amsterdam, KVK 98832387, VAT NL005356044B21, email info@atherium.nl.
What data I process
Contact form: name, email address, website address and your message — solely to answer your request. Chat on this site: the text you enter is processed by an external processor in the EU to generate a reply automatically; do not enter personal data. Wtta reminder: if you ask for it, I keep your agency’s name and your WhatsApp number or email address to send you one reminder on 1 November, and delete them afterwards. Server logs: technical data (such as IP address) for security and debugging. Every request you send through a form on this site is stored on my server (Hetzner, Germany), and a copy of every contact request and demo request is kept in my own customer records on the same server. By email I only receive a notice that a new request has arrived, without its content.
No cookies or tracking
This website uses no cookies and no advertising or tracking scripts. Visitor statistics are cookieless and anonymous.
Retention and sharing
I keep requests no longer than needed to handle them, and at most six months after the last contact; server logs for at most thirty days. If you become a client, invoice data falls under the statutory seven-year retention obligation. I never sell your data and only share it with processors needed to run the site (hosting in the EU and the provider of the website chat, also in the EU).
Demo request
The demo forms let you request a demo. I then process the company name, your description, your WhatsApp number and any photos you attach — solely to build the demo and reply to you. I keep such a request for at most six months and do not share it with anyone.
Legal basis
I process your data to take steps at your request before entering into a contract (article 6(1)(b) GDPR) and, for security and debugging, on the basis of my legitimate interest (6(1)(f)).
Your rights
You have the right to access, correct, delete, restrict and port your data, and to object to processing (GDPR). Email info@atherium.nl and I will take care of it. If you disagree with how I handle it, you can lodge a complaint with the Dutch data protection authority, the Autoriteit Persoonsgegevens.
Outreach emails to businesses
Sometimes I contact businesses by email: to offer a website, to offer web and marketing agencies white-label production of websites and booking apps, or a referral partnership, or to show staffing agencies, labour-supply firms and building-cleaning companies in Belgium a personal demo of my app for planning, documents and hours, or to show building and installation firms in Belgium (windows, doors and verandas, roofing, heat pumps and solar panels) a personal demo of a quote-request page. This section explains what data I use for that and what your rights are.
Emails that offer garages and body shops a demo of an online booking page (in Belgium) have their own notice below: Emails to garages and the booking demo.
Who is responsible
Atherium (Mark Yushkevich), sole proprietorship, Jelle Posthumapad 72, 1106 ZR Amsterdam, the Netherlands. Dutch Chamber of Commerce (KvK) no. 98832387. Contact: info@atherium.nl.
What data I use
The company name, the business email address, and other business details that are publicly listed, such as the business address, the website address, the legal form, the company number and the type of business. I also keep a record of the emails I sent, any replies, and opt-outs. I contact generic business addresses (such as info@) where possible; in Belgium, only generic addresses of companies. For the app demo I may also use the name of a director or contact person as published in a public company register or on the business's website. It appears only inside that business's demo, as the office user. For the quote-request demo, I also use the logo, colours and photos of the firm's own work from its public website.
Where the data comes from
Public sources only: OpenStreetMap; the Belgian Crossroads Bank for Enterprises (KBO/BCE: legal form, enterprise number and registered office) or, for a company registered in another country, that country's public company register; public lists of recognised employment agencies; published annual accounts and business directories; and the business's own website, where I find the published contact address. Every email says where the contact address and the business details come from.
Why, and on what legal basis
To send one offer and a limited number of follow-ups: for a website, white-label or partnership offer, at most one follow-up; for the app demo, at most two follow-ups, so no more than three emails over about two weeks. For the personal quote-request demo, at most one follow-up, so no more than two emails. The legal basis is my legitimate interest in offering my services to businesses (Article 6(1)(f) GDPR). I keep this interest proportionate: business addresses only, no more than three emails, and an easy way to opt out.
The website preview
For some firms, I build a concept of a new homepage under the firm's name. It uses only publicly available business information (the firm's name, contact details and services) and, where available, its logo and photos it has published online, supplemented where needed by stock photos. The concept is marked as a concept and is not indexed by search engines. Its link contains a short code for the firm, so that I can see whether the concept was opened; these statistics work without cookies. Anything a visitor types or uploads stays in their own browser; nothing is sent to the firm or to me. The concept goes offline after a few weeks, and on request within one working day. I delete its files within 30 days after it goes offline.
The personal app demo
The demo shows the business's name, logo and public contact details, with sample people, sites and hours. It is not indexed by search engines. Its link contains a short code for the business, so that I can see whether the demo was opened (statistics without cookies). Anything a visitor types stays in their own browser. The demo goes offline on the date stated in my email; I delete the business's demo files within 30 days after that. On request, I take the demo down within one working day.
The personal quote-request demo
For building and installation firms, I build a demo of a quote-request page under the firm's name. It shows the firm's name, logo and colours, its public contact details (address, phone, email) and a selection of photos of its own work from its public website, supplemented where needed by stock photos, together with sample products and example prices. The demo is not indexed by search engines. Its link contains a short code for the firm, so that I can see whether the demo was opened; these statistics work without cookies and without storing IP addresses. Anything a visitor types or uploads stays in their own browser; nothing is sent to the firm or to me. The demo stays online for three working days from the date of my email. On request, I switch it on again. I delete the demo files within 30 days after it goes offline, and on request within one working day.
Who else processes the data
My email provider (Zoho Mail, EU data centre) and the host of the preview sites and app demos (Hetzner Online GmbH, Germany). I do not sell or share your data for anyone else's marketing.
How long I keep it
If you don't reply, I delete your data within 90 days of my last email; after that I keep only a one-way hash of the address, so that you are not contacted again. If you opt out, I keep only your email address on a suppression list (stored as a one-way hash), so that you are never contacted again. If you reply, I keep the correspondence as long as needed to handle your request. If we agree on a project, I keep the related records for 7 years, as Dutch tax law requires.
Your rights
You can object at any time — your objection to direct marketing is always honoured. Reply "unsubscribe" or use the link in the email, and I stop before the next send. You can also ask for access, correction or deletion of your data by writing to info@atherium.nl. You have the right to complain to the Dutch Data Protection Authority (Autoriteit Persoonsgegevens, autoriteitpersoonsgegevens.nl). Recipients in Belgium can also contact the Belgian Data Protection Authority (Gegevensbeschermingsautoriteit / Autorité de protection des données, dataprotectionauthority.be).
No automated decision-making or profiling is used.
Until 10 October 2026 I also emailed businesses in the United Kingdom. The UK GDPR applies to their data, and they can complain to the ICO (ico.org.uk). I delete that data within the same periods: 90 days after my last email, after which only a hash stays on the suppression list.
Emails to garages and the booking demo
Sometimes I email independent garages and body shops to offer online booking. Before I write, I build a working demo of a booking page with the business’s own name, so the owner can try it instead of reading about it. This section explains what data I use for that and what your rights are.
Who is responsible
Atherium (Mark Yushkevich), sole proprietorship, Jelle Posthumapad 72, 1106 ZR Amsterdam, the Netherlands. Dutch Chamber of Commerce (KvK) no. 98832387. Contact: info@atherium-websites.nl, the address these emails are sent from, or info@atherium.nl.
What data I use
- Business details published on your own website: the company name, the business email address and phone number, the address, opening hours, services and prices, and the logo and photos shown there.
- For Belgian companies: the legal form and enterprise number from the Crossroads Bank for Enterprises (KBO/BCE).
- A record of the emails I sent, any replies and opt-outs.
- How the demo is used: when it was opened, which screens were used, the device type, browser language and time zone. I don’t store IP addresses and don’t use advertising cookies.
I write to generic business addresses (such as info@) wherever possible.
Where the data comes from
Public sources only: the business’s own website, OpenStreetMap and the KBO/BCE register (Belgium). Every email says where I found your address.
Why, and on what legal basis
To send one offer, the demo, and at most one follow-up. The legal basis is my legitimate interest in offering my services to businesses (Article 6(1)(f) GDPR). I keep this proportionate: business addresses only, no more than two emails, and an easy way to opt out.
The demo
The demo uses only information that is public on your website. It is hidden from search engines, it stays open for 3 days from the first time it is opened, and test bookings made in it go nowhere. If you’d like it removed, reply to my email: I take it down within one working day.
Who else processes the data
My email provider (Zoho Mail, EU data centre) and the host of the demos and of this website (Hetzner Online GmbH, Germany). I do not sell or share your data for anyone else’s marketing.
How long I keep it
- If you don’t reply, I delete your data and the demo within 90 days of my last email. After that I keep only a one-way hash of the address, so that you are not contacted again.
- If you opt out, I keep only your address on a suppression list, stored as a one-way hash, so that you are never contacted again.
- If you reply, I keep the correspondence as long as needed to handle your request. If we agree on a project, I keep the related records for 7 years, as Dutch tax law requires.
Your rights
You can object at any time; an objection to direct marketing is always honoured. You can also ask for access to your data, a correction or deletion. Just reply “no thanks” or “unsubscribe” to any of my emails, or write to info@atherium-websites.nl.
You can complain to a data protection authority: the Autoriteit Persoonsgegevens (Netherlands) or the Gegevensbeschermingsautoriteit / Autorité de protection des données (Belgium).
Until 10 October 2026 I also emailed garages in the United Kingdom. The UK GDPR applies to their data, and they can complain to the ICO (ico.org.uk). I delete that data within the same periods: 90 days after my last email, after which only a hash stays on the suppression list.
Questions about your data?
Email me and I will take care of it.
info@atherium.nlAtherium · Amsterdam · KVK 98832387