I am probably a miserable talker, as usually after my introduction of rationality/singularity related topics people tend to even strengthen their former opinions.

I'm not sure this is what you're doing, but I'm careful not to bring up LessWrong in an actual argument. I don't want arguments for rationality to be enemy soldiers.

Instead, I bring rationalist topics up as an interesting thing I read recently, or as an influence on why I did a certain thing a certain way, or hold a particular view (in a non-argument context). That can lead to a full-fledged pitch for LessWrong, and it's there that I falter; I'm not sure I'm pitching with optimal effectiveness. I don't have a good grasp on what topics are most interesting/accessible to normal (albeit smart) people.

And, how does this actually help your own intentions? It seems non-trivial to me that finding a utility-function where taking the time to improve the rationality-q of a few philosophy/arts students or electricians or whatever is actually a net-win for what one can improve. Or is everybody here just hanging out with (gonna-be) scientists?

If rationalists were so common that I could just filter people I get close to by whether they're rationalists, I probably would. But I live in Taiwan, and I'm probably the only LessWrong reader in the country. If I want to talk to someone in person about rationality, I have to convert someone first. I like to talk about these topics, since they're frequently on my mind, and because certain conclusions and approaches are huge wins (especially cryonics and reductionism).