@cy
That's a good point, and I would agree that sharing *sensitive* information before establishing a secure link is not advisable (e.g. your bank information), but I think what different systems use to establish that differs. Like someone talking about the weather and whatnot doesn't really tell me what they think is Interesting or important, so it's harder to establish a motivational base. But I think that it's also about what kind of relationship you're trying to establish, so the different protocols are adapted to that, rather than being strictly one is better than the other.