Probably there is more: It is also useful to show ads to non-paying friends, valuable to sell to data brokers, and made available to 3-letter agencies. For an

Probably there is more: It is also useful to show ads to non-paying friends, valuable to sell to data brokers, and made available to 3-letter agencies. For an analysis of the graph between users, does a link between two users break when one is paying or both? Don't they even track graphs beyond non-user, e.g., same non-user phone number in two user address books?