Do cookie banners receive different acceptance rates on desktops and on smartphones?


Most cookie banners can be classified into one of three general categories: (1) notice only banners, (2) notice + opt-out banners, and (3) notice + opt-in banners.  If a company chooses to adopt a cookie banner that provides notice and solicits the opt-in consent (e.g., “I agree”) of website users, the company would have a strong argument that it does not need to disclose that it has sold information, does not need to forward deletion requests to the providers of its third party cookies, and does not need to include an “opt out of sale” link on its website.1

Companies often struggle with anticipating the percentage of users that are likely to accept the deployment of cookies when prompted.  There is relatively little empirical data publicly available concerning website visitors’ interactions with cookie banners.  The little data that does exist, however, indicates that user acceptance rates are significantly greater when a user visits a website on their smartphone.  For example, in one study researchers placed the same cookie banner on the bottom-left of a website and on the bottom left bottom-left of a smartphone.2 They found that desktop visitors accepted the banner 18.4% of the time, whereas smartphone visitors accepted the same banner 26.4% of the time.  When other variables were controlled the difference increased.  So, for example, when the banner was adjusted to present only two options – accept or decline – the acceptance rate increased to 45.6% for smartphones while it remained around 20% for desktop users.3 The increase was likely caused by presenting options that were, from a user-experience perspective, easy to select on a smartphone.