This is a great perspective tool; it gets me looking for who benefits from providing the “free” service or item.
Facebook and Google sell your information (directly and indirectly) to companies so they can better sell you things. Free samples attempt to create paying customers. Politicians gain favor and votes to retain their jobs. Parents attempt to produce badass new humans, who will eventually [pay to] care for them as they get older.
A subset of “follow the money”, and “everything is done for a reason”.
This may come off as obscenely cynical; its more an honest look at the transactional nature of all interactions.
(I’m at a bad 28hrs+, and brain is stonewalled on editing: apologies if this is unacceptably disjointed or poorly communicative.)