If you're friending me just to get my responses to your Plurks, then first check if we have the same interests. That should be easy enough to tell from my Plurks. I don't like pointless threads littering my timeline, so I don't often friend back.
Smart life choices: reading depressing manga while alone in another country counting down the hours to work I'm not familiar with, with the reminder that I haven't done any reviewing yet hanging over my head.