Although Facebook users have the ability to find out how the website’s algorithm categorises their interests to tailor advertising via the ‘your ad preferences page’, 74% of the 943 adult Facebook users surveyed for the research did not know this list existed.

When directed to the page as part of the research, half ( 51%) of participants said they are not comfortable with the company compiling this information.

Information displayed on this page includes ‘categories’ – a list of the person’s interests according to Facebook’s algorithm, based on data provided by the user and their engagement with content on the site (through posts, likes, comments and shares).

The information can include demographics, social networks and relationships, political leanings, life events, food preferences and hobbies, which advertisers use to target audience segments.

Over half ( 59%) of Facebook users surveyed say the categories listed on the page reflect their real interests ( 13% felt the list very accurately reflects their interests, while 46% felt it was somewhat accurate). Meanwhile, while 27% said they are ‘not very' ( 22%) or ‘not at all' ( 5%) accurate.

Around half of the survey’s participants ( 51%) had been assigned a political category on the site. Among these, 73% said the platform’s categorisation of their political perspective is ‘very’ or ‘somewhat’ accurate, while 27% said their categorisation is ‘not very’ or ‘not at all’ accurate. 

Methodology
The analysis is based on a nationally representative survey conducted from 4th September to 1st October 2018, among a sample of 963 US adults ages 18 years and older who have a Facebook account. The margin of error for the full sample is plus or minus 3.4 percentage points. The survey was conducted by GfK in English and Spanish using its KnowledgePanel.