One of the fabled 4 U’s according to Michael Masterson’s copywriting course is ultra-specificity. The others are urgency, usefulness and unique in case you were wondering.
That’s the rule. Sometimes it’s appropriate to break the rules. The big question is how.
NLP breaks this rule by saying that if you leave certain things purposefully vague, people will fill in with their own meaning. That way the copy looks more like it’s speaking more directly to their desires. This is called generalization.
Done artfully, it will increase response. Done sloppy or haphazardly and it will look amateurish. The trick is to figure out which things to leave vague.
The best example I can think of was what our drill sergeants used to say in the army. If someone screwed up they might say they had something for the offender when he got back to the barracks. Sometimes they forgot by then and sometimes it was more unpleasant "correctional" training.
The point is that they left unnamed the something they had in store. The terror of wondering the fate that awaited was more than adequate to get you in line for the time being.
Doing it can get you what you really want.