The other examples are decent (if you explicitly opt-in, not just mindlessly click a checkbox), but that Facebook one...seriously? It is extremely disappointing to see someone use that as an example of "good manipulation" on a site like this non-sarcastically. How could it be good for a corporation to hire psychologists to manipulate customers into spending more time on their product? Especially a product that is known to negatively affect mental health. It's hardly any different from Joe Camel trying to push kids to smoke.
The effort was precisely to offer a different objective than time spent on the site, that is a reasonable first approximation for usability and relevance, but not a good self-referential objective. There is evidence that mirroring content has a positive psychological impact.
- Freedom, RescueTime do that for your web-use;
- my bank (Monzo) and a stealth company by alumni thereof do it for your spending.
There have also been a lot of efforts at Facebook to show you content that would lead you to have more positive interactions, like posting similar things yourself rather than be a passive spectator.
I’m involved in several of those projects.