The product of Less Wrong is truth. However, there seems to be a reluctance of the personality types here - myself included - to sell that product. Here's my evidence:

Yvain said: But the most important reason to argue with someone is to change his mind. ... I make the anecdotal observation that a lot of smart people are very good at winning arguments in the first sense [(logic)], and very bad at winning arguments in the second sense [(persuasion)]. Does that correspond to your experience?

Eliezer said: I finally note, with regret, that in a world containing Persuaders, it may make sense for a second-order Informer to be deliberately eloquent if the issue has already been obscured by an eloquent Persuader - just exactly as elegant as the previous Persuader, no more, no less.  It's a pity that this wonderful excuse exists, but in the real world, well...

Robin Hanson said: So to promote rationality on interesting important topics, your overwhelming consideration simply must be: on what topics will the world’s systems for deciding who to hear on what listen substantially to you? Your efforts to ponder and make progress will be largely wasted if you focus on topics where none of the world’s “who to hear on what” systems rate you as someone worth hearing. You must not only find something worth saying, but also something that will be heard.

We actually label many highly effective persuasive strategies that can be used to market our true ideas as "dark arts". What's the justification for this negative branding? A necessary evil is not evil. Even if - and this is a huge if - our future utopia is free of dark arts, that's not the world we live in today. Choosing not to use them is analogous to a peacenik wanting to rid the world of violence by suggesting that police not use weapons.

We treat our dislike of dark arts as if it's a simple corollary of the axiom of the virtue of truth. Does this mean we assume the ends (more people believe the truth) doesn't justify the means (persuasion to the truth via exploiting cognitive biases)? Or are we just worried about being hypocrites? Whatever the reason, such an impactful assumption deserves an explanation. Speaking practically, the successful practice of dark arts requires the psychological skill of switching hats, to use Edward de Bono's terminology. While posting on Less Wrong, we can avoid and are in fact praised for avoiding dark arts, but we need to switch up in other environments, and that's difficult. Frankly, we're not great at it, and it's very tempting to externalize the problem and say "the art is bad" rather than "we're bad at the art".

Our distaste for rhetorical tactics, both aesthetically and morally, profoundly affects the way we communicate. That distaste is tightly coupled with the mental habit of always interpreting the value of what is said purely for its informational content, logical consistency, and insight. I'm basing the following question on my own introspection, but I wonder if this almost religiously entrenched mental habit could make us blind to the value of the art of persuasion? Let's imagine for a moment, the most convincing paragraph ever written. It was truly a world-wonder of persuasion - it converted fundamentalist Christians into atheists, suicide bombers into diplomats, and Ann Coulter-4-President supporters into Less Wrong sycophants. What would your reaction to the paragraph be? Would you "up-vote" this work of genius? No way. We'd be competing to tell the fundamentalist Christian that there were at least three argument fallacies in the first sentence, we'd explain to the suicide bomber that the rhetoric could be used equally well to justify blowing us all up right now, and for completeness we'd give the Ann Coulter supporter a brief overview of Bayesianism.