They spam heaps before hand, or waste time trying to find places they can put useful input in. What I think aNILEator meant was that was his guess at what the thread title was about.
My guess is that after someone posts something, they have to make 5 other non-spam posts before somebody will come and answer their question for them. Which is completely ridiculous as far as I can see...
Anyway personally, it does seem "weird" that someone posts, you answer, and you never see them again. I guess you could compare it to meeting someone on the street having a brief conversation and never seeing them again. But it's not "annoying" as such. Anyway I like helping people, if they give you good feedback you get an ego boost
/ 
