  Since the adoption of the General Data Protection Regulation (GDPR) in May
2018 more than 60 % of popular websites in Europe display cookie consent
notices to their visitors. This has quickly led to users becoming fatigued with
privacy notifications and contributed to the rise of both browser extensions
that block these banners and demands for a solution that bundles consent across
multiple websites or in the browser.
  In this work, we identify common properties of the graphical user interface
of consent notices and conduct three experiments with more than 80,000 unique
users on a German website to investigate the influence of notice position, type
of choice, and content framing on consent. We find that users are more likely
to interact with a notice shown in the lower (left) part of the screen. Given a
binary choice, more users are willing to accept tracking compared to mechanisms
that require them to allow cookie use for each category or company
individually. We also show that the wide-spread practice of nudging has a large
effect on the choices users make. Our experiments show that seemingly small
implementation decisions can substantially impact whether and how people
interact with consent notices. Our findings demonstrate the importance for
regulation to not just require consent, but also provide clear requirements or
guidance for how this consent has to be obtained in order to ensure that users
can make free and informed choices.
