It's not as contradictory as it sounds. Many such practices are fairly well know to general audiences from causal reading of articles just like this, but the practices often aren't identified as such by those who are subjected to it, or if it is identified, the practice works regardless. Take for example here on HN the large number of people who dismiss many of the practices of social media likes but get upset when their post is downvoted.

Such practices have a major effect on people regardless of how aware they are of what's actually going on.