The point seems to me to be that social media groups are identified who do know what they want, or at least who hold a strong belief that they know what they want. Animal rights, for example, can unleash passionate violence in people. The trick then is to persuade those people, by fine-grained delivery of ads, that what they want is part of some more general scheme. Force-feeding geese and bull-fighting are evil, they are permitted in Europe, therefore the EU is evil, I am going to vote for Brexit.

Otherwise, you're right that the methods used are fundamentally those the advertising industry has been using for over half a century. The difference in speed and fine-grained delivery doesn't create a new paradigm, it does, however, up the game enormously. To the point where one may fairly say, this is a whole new ball game.

Things are going to slide, slide in all directions
Won't be nothing
Nothing you can measure anymore
L. Cohen