Re:What Data Does Facebook Collect When I’m Not Using Facebo...
by mgummelt on Monday April 16, 2018 @05:18PM
(#16852879)
They don't allow advertisers to target non-users. I'm sure they use non-user data for clustering, just as you described.
They also probably use it when the user finally does create a FB account.
In other words, I see the benefit to FB of being able to say "Person A likes 1, 2, 3; User B likes 1 and 2 - perhaps they also like 3?" where A is a non-user and B is a FB user, but I don't see the benefit derived from identifying Person A to advertisers if they can only target that person on FB, where they aren't a user?