Quote:
Originally Posted by ITraffic
i notice that my viewing habits are getting ads served up on other sites now. how is that being done? like i watch some videos on youtube and get served similar ads on fb and the reverse. or i google something and all my ads on fb are from sites i googled and visited.
|
ELI5:How does Facebook target-advertise the very product I just looked up in Google/other websites, despite me being logged out of my account at the time? : explainlikeimfive
Some websites include Widgets from other sites, such as Facebook, Twitter and Google, to add interactivity and social features to their own websites. For example, these widgets might show recent tweets by the website's organization or allow you to 'Like' the website on Facebook.
When websites incorporate Facebook social widgets, it is known that Facebook sets a tracking cookie - the infamous datr cookie. This cookie is set to a unique value that identifies you, or more accurately it identifies your computer. It is set no matter whether you are logged-in or even if you don't have a Facebook account.
As you surf the web, browsing a range of seemingly unconnected websites. Each time you visit a page with a Facebook widget, you are telling Facebook the URL of page your visiting, your approximate location (through your IP address) and the value of the hidden tracking cookie.
Although this cookie is just a unique number (and therefore often described as 'anonymous') the fact that Facebook can work out almost every site you have ever visited gives them a profile to work on. Therefore every website that has Facebook integration is unwittingly facilitating Facebook in tracking your browsing habits. As the number of sites with 'Share with Facebook' buttons and 'Log in using Facebook' options grows, the data Facebook is collecting becomes more complete.
To make matters worse, when you later log in to Facebook from the same computer, Facebook is able to match the tracking cookie with your username, and they also have a wealth of other information from your personal profile, your friends activities, your previous activity on Facebook, your location history (from Mobile Facebook) and so on. At this point, they can target advertising quite successfully.
This is highly controversial activity and Facebook has previously both denied it uses these techniques and claimed they are a 'bug' in their software. However, software engineers, 'hackers' and academics have revealed this behaviour by studying browser and network activity.