I don’t think anyone is really claiming that people make all their purchases impulsively; most people probably make most of their purchases in an educated way - unless you are very wealthy, you basically have no other choice. That said, everyone will act impulsively some fraction of the time, and some more than others. I’m not particularly susceptible to most targeted advertising, but there are a few memorable times where I’ve bought things (I.e. Brooklinen sheets and an Aer backpack) because of targeted ads on FB. It’s reasonable to think that other people who do less research generally would be much more susceptible to targeting. If you’re able to influence only 2% of all consumer purchases with targeting, that’s still an obscene amount of money.