Kevin, can you clarify what you mean by "real chance" when you say

We try to take existential risk seriously around these parts. Each marginal new user that reads anything on Less Wrong has a real chance of being the one that tips us from existential Loss to existential Win.

?

Your statement is clearly true, but so is the statement "there's a real chance that there are unicorns in Asia" which is nobody makes. How likely do you think it is that Less Wrong will prevent an existential risk?

For concreteness, I'll say that I personally view Less Wrong and the dating website OkCupid as having similar order of magnitude likelihood of making a difference. Both websites connect smart people. Less Wrong's population is smarter and more interested in existential risk than OkCupid's population. But OKCupid reaches many more people than Less Wrong does (having something like 1.2 million members) and I don't think that what people do on Less Wrong is so much more valuable than what people do on OkCupid for Less Wrong's superior content to swamp the size difference between the two communities.