That's just another trick to make you a more convincing salesman, like smiling. Of course they drill that into your head during the unpaid training for Cutco, and hey, those knives are pretty badass, I still have and use my demo set. It doesn't change the fact that I feel like "Well, if my product really is the best on the market, what do you need me to tell you for? The truth is out there, it doesn't have to come from me." I'm perfectly comfortable with giving a list of facts about my theoretical product and why it's awesome, or making people aware of its existence, what I'm not comfortable with is making a story to get you to want it or pressure you into believing everything I say, and I definitely don't like rhetorical devices used for selling.

Yet even PG's advice is product-focused rather than selling-focused; can you distinguish PG's advice from a simple bulleted fact-list? (And how well do you think that alone will sell your product?) If your product isn't the best on the market (or so you think), taking PG's advice would tell you to get back to work while a hustler would go out and sell it anyway. (They don't even necessarily have to lie about anything.) PG's approach echoes the traditional programmer reply of why he doesn't need a marketing team or need to study marketing by saying "My product will speak for itself."

Anyway, can you link to an essay or post from PG where he said that? A quick Google search didn't turn up a source.