Definition
Consent should be specific, informed, unambiguous, cover all processing activities, and not inferred from silence or pre-ticked boxes, must be clear, concise and non-disruptive.
Excerpt
Consent should be given by a clear affirmative act establishing a freely given, specific, informed and unambiguous indication of the data subject's agreement to the processing of personal data relating to him or her, such as by a written statement, including by electronic means, or an oral statement. This could include ticking a box when visiting an internet website, choosing technical settings for information society services or another statement or conduct which clearly indicates in this context the data subject's acceptance of the proposed processing of his or her personal data. Silence, pre-ticked boxes or inactivity should not therefore constitute consent. Consent should cover all processing activities carried out for the same purpose or purposes. When the processing has multiple purposes, consent should be given for all of them. If the data subject's consent is to be given following a request by electronic means, the request must be clear, concise and not unnecessarily disruptive to the use of the service for which it is provided. - Recital 32 of Regulation 2016/679
Related cases
Planet49 ran a promotional lottery competition on its website. To play in the lottery, users were required to tick a checkbox to receive third-party advertising, otherwise they could not play. Also, the registration process included a pre-ticked checkbox that would allow tracking of their online behaviour.