That advice was actually given in the context of a supervisor or superior working to improve a report: 'Praise the slightest improvement and praise every improvement. Be “hearty in your approbation and lavish in your praise.”'
So in context, its about noticing the things you as a person like about people and vocalizing them, and separately drawing attention to when someone improves. Pretty sound advice
If you read the actual book, its as much about not being a bore, and how not to piss people off. Some people take the advice in it WAY too far, and that's when it comes across as off-putting and inauthentic.
Because you know they took the compliment sandwich advice to heart, and the other shoe is about to drop.
Had no idea it had a name or “strategy” associated with it… I just like other people to know when they’re having a positive impact on me (or something else). And people always seem to like knowing that, and get into a better mood in response!
Edit: maybe I’m not understanding the concept very well, and “profuse praise” the strategy is more belligerent than I thought
For example, throwing in phrases like "with your experience, you would know that..." or "that thing you said was hilarious" make people feel good, hopefully while also being true. This is a huge part of likeability.