[…] a salesman’s ultimate overriding motivation is self-interest – if you buy what he’s selling, the salesman profits. So even though the salesman may have a very powerful, charismatic, admirable personality, and might even persuade you that buying is in your interests (and it really might be) – still, a little part of you always knows that what the salesman’s ultimately after is something for himself. And this awareness is painful… although admittedly it’s a tiny pain, more like a twinge, and often unconscious. But if you’re subject to great salesmen and sales pitches and marketing concepts for long enough – like from your earliest Saturday-morning cartoons, say – it’s only a matter of time before you start believing deep down that everything is sales and marketing, and when somebody seems to care about you or about some noble idea or cause, that person is a saleman and really ultimately doesn’t give a shit about you or some cause but really just wants something for himself.
[David Foster Wallace in “UP, SIMBA”]