If you know the history of advertising, "hacking our brains" is actually kind of amusing. Ad companies have been employing psychologists ever since the 1950s to figure out how to induce feelings - insecurity, envy, warmth, guilt... you name it, that translate to desire for a product. Classic example is implying that products will increase your sex appeal - not by literally telling you that, but by showing you their little scenarios where using Product X suddenly makes someone hot. Ooooooh, says the young blond in the halter top, you had your taxes done by H&R Bloch? Let me loosen these panties!
Using data about a person to gauge what kind of a deal they might be willing to make is a centuries=old negotiating technique known as "negotiating". Sales people and other business people are always looking for better ways to do it, and now they've found AI to help them. Nobody's hacking anybody's brain, they're just putting expert salesmanship in a box.