Such algorithms don't necessarily KNOW that you bought a fridge. They certainly change tack, however, when you stop clicking on those ads or click on others, or any of countless and unknowable other cues.

Other than some small number of exceptions(). I am not convinced that marketing budgets are fluff.

() Huy Fong Foods (Siracha Hot Sauce) -- that's literally the only product company I can think of that doesn't do marketing, apparently?

Huy Fong marketed by networking within the Vietnamese immigrant communities of Southern California. Marketing is literally every action taken that results in sales - not merely paid advertising alone.