I'm not entirely sure what goes into me deciding to rep someone. I guess if someone comes across as friendly, intelligent, informative, fair and clear that's what makes me think about repping them. Being funny also helps, but I doubt I'd ever up-vote someone solely for that quality. I've been here roughly 7 months and I think I've maybe repped 5 - 7 people. I usually only remember the rep system when a post really strikes me.
And on topic: I'm glad there isn't a negative rep available.
And on topic: I'm glad there isn't a negative rep available.