Article 4.1 itself, as it goes on, defines personal data in a way that it relates specifically to that which can identify someone, so it doesn't mean literally anything about the ad placement simply because a person is seeing the ad. Definition of personal data: "any information relating to an identified or identifiable natural person (‘data subject’); an identifiable natural person is one who can be identified, directly or indirectly, in particular by reference to an identifier such as a name, an identification number, location data, an online identifier or to one or more factors specific to the physical, physiological, genetic, mental, economic, cultural or social identity of that natural person."