Advertising does work, yes, but only for products in which demand already exists. No significant amount of people will buy a hand-cutting-off machine no matter how it is advertised.

The radicalization began decades ago, initially couched in racial resentment, and has spread largely via Americans' innate dissatisfaction with government, which goes back literally hundreds of years.

This resentment has certainly been fostered, even engineered, and I would separate those who have directly engineered or manipulated such resentment (e.g. Benghazi trials, trans panic, Critical Race Theory) with those who merely profit from it.

Two very different groups, imo.