The dirty secret is: it isn't effective. It's just that the funnel is the only channel incumbent sales and marketing people allow to exists (hence the bonfire),

The dirty secret is: it isn't effective. It's just that the funnel is the only channel incumbent sales and marketing people allow to exists (hence the bonfire), so for lack of alternatives it just seems effective. Basically the author is describing how to construct and maintain a self-fulfilling prophecy. The fact that this whole funnel is completely superfluous for almost anything but bespoke services has been proven by the internet for while now. Anything from online shopping, booking vacations to self-service advertising works just fine without hordes of salespeople.