I have a couple of friends now describe this, one I have dated in the past. They have talked about working out how to flatter people in early days of friendships/relationships to win them over. One described how good he is at working out how to flatter someone/what their "thing" is and I can see very clearly how he employed this tactic (successfully!) with me.
I know it's a good social skill to ask people about themselves, take an interest. But this sort of flattery feels a bit fake.