> Why do you think that data is valuable?
If I am not logged in and I have "Do Not Track", it's illegal for them to track my usage for marketing purposes, let alone show me personalized ads.
The only way they are allowed to legally monetize data for marketing purposes is to find other users that don't have do-not-track + opted in for marketing targeting, and show the ads to them.
Additionally, they can (and do) utilize bulk usage data (from many people) by feeding it into their ecosystem. For example, a video about cats being more popular than another will pop up higher on the search rankings when somebody searches for "cat". User "labor"/interest moderates the content on the platform, which makes it more attractive, and increases the overall number and engagement of users. Out of those users there is some % that have opted in for marketing, and can be legally targeted by personalized ads.
The only way they are allowed to legally monetize data for marketing purposes is to find other users that don't have do-not-track + opted in for marketing targeting, and show the ads to them.
Additionally, they can (and do) utilize bulk usage data (from many people) by feeding it into their ecosystem. For example, a video about cats being more popular than another will pop up higher on the search rankings when somebody searches for "cat". User "labor"/interest moderates the content on the platform, which makes it more attractive, and increases the overall number and engagement of users. Out of those users there is some % that have opted in for marketing, and can be legally targeted by personalized ads.