The experience of reading a comment knowing the commenter's id makes up (a little bit at least) for the lack of face2face. For example, based on a previous discussion, I know that mixmax had sex with a porn star :) When I read his comments now, my brain does some signal processing magic using this. Please note that I don't give him a +1 coz of this history. But this knowledge puts warmth in an otherwise cold place (cold = place filled with strangers).
