It's kinda like when someone twitters you, but you aren't looking at your twitter and so by the time you get to it, the comment has been lost in a sea of other comments. I always feel so bad when people tell me that I missed one of their comments.

Awww Thanks Totally didn't see that you wrote on my DDN wal-type-thingy till today

Hey Believe, Thanks for helping me change my avatar, haha