On YouTube, it's the pointless race and subsequent claiming of first comment of a particular video, especially one on a heavily-subscribed channel which would result in masses of people watching as soon the video is posted. Ironically, the user who childishly claims first comment as though they won the lottery is often given a very negative rating and a harsh response from more rational viewers due to the fact that noone truly cares about who has the first comment.
A classic example of First Stupidity, as taken from an actual video comments page, minus real usernames.
<Tuber1> first (-6 rating)
<Tuber2> who gives a shit you dumbass
<Tuber1> you can rate this down all you want, but i still got first lololololololol (-13 rating)
<Tuber3> and your a dumb faggot who spends all his time just saying first get a life junior
<Tuber1> FIRST!! LOLOLOLOLOLOOOLOLOLOLOL