I was a member of a bustling forum with hundred, perhaps thousands of new users a day. If a new user would surface, it would not take long for them to leave an impression even with all the noise. As long as they were posting something interesting to me. I would remember small things about the user that would help me build a mental profile, things like fonts, sigs, avatars and badges, name.

That's been lost with Facebook, Reddit. There is a lack of personality from one comment to another, no distinguishable visual factor to aid distinction or a contrast . I think Humans appreciate the slight difference to tell people apart. Aside from a username, maybe it is not enough.