citizenM says:

we use cookies (we also sell cookies in canteenM, but that's another story)

We use marketing cookies and similar techniques to collect your data, but it’s only in order to show you offers and things we think you’ll like. Third parties can store tracking cookies (for the purpose of targeted advertising) and social media cookies (for instance to enable a "like" button). These cookies are stored on your device or in your browser and are used by us and third parties to track your internet behavior on and outside our website. We also use cookies and similar techniques for technical reasons and to optimize the user experience on our websites.  By clicking “I agree” you consent to the use of marketing cookies and third party tracking cookies. You can withdraw your consent at any time by setting your browser to disable cookies and/or to remove all cookies from your browser. Please read the Cookies section in our Privacy Statement to learn more about the cookies used on our website.