1. Amazon passed your [IP address + SKU browsed] to facebook ad platform. And facebook knows from there on.
2. Facebook snoops on your audio and its ad platform pulled SKU from amazon.
3. You have various extensions on your browser which can "read all websites data you visit" - which have sold your browse information with IP to facebook.
Third is most likely.
+ I have noticed - "somehow" my facebook learns what I watch in youtube and vice-versa. Only way this could happen is via one of my "trusted" browser extension!
If you are logged in on both services then they just need to load a resource from the other service. The request sends cookies. They used to call this 1x1 or tracking pixel.
Looks like youtube doesn't talk to Facebook directly. It does talk to doubleclick though. I recommend installing uMatrix to manage loading 3rd party resources.
But that assumes all tracking occurs client-side. YouTube, Amazon, etc. doesn't _need_ to track you client-side; they can report usage statistics for the current user (i.e. you) server-side and there's no way that you can stop them from doing so via a browser extension.
Comments
Below are the scenarios:
1. Amazon passed your [IP address + SKU browsed] to facebook ad platform. And facebook knows from there on.
2. Facebook snoops on your audio and its ad platform pulled SKU from amazon.
3. You have various extensions on your browser which can "read all websites data you visit" - which have sold your browse information with IP to facebook.
Third is most likely.
+ I have noticed - "somehow" my facebook learns what I watch in youtube and vice-versa. Only way this could happen is via one of my "trusted" browser extension!
If you are logged in on both services then they just need to load a resource from the other service. The request sends cookies. They used to call this 1x1 or tracking pixel.
Looks like youtube doesn't talk to Facebook directly. It does talk to doubleclick though. I recommend installing uMatrix to manage loading 3rd party resources.
But that assumes all tracking occurs client-side. YouTube, Amazon, etc. doesn't _need_ to track you client-side; they can report usage statistics for the current user (i.e. you) server-side and there's no way that you can stop them from doing so via a browser extension.