u can use karma to change the name in your timeline and using emoticons in your plurk post.. (I think that's the use of karma points)

that's what I know.. (I'm still new here anyway)..

if you Plurk regularly, karma goes up & you get more emoticons. Otherwise it goes down.

it's how we get addicted to Plurk.

and if you're going to have a vocation like me, then u can freeze karma

by this way, ur karma won't go down