I usually upvote stories to save them or mark them to-read. I don't vote up to thank or agree, though I still do it, subconciously. I reply with a thanks instead. I'm probably starting to rely on other users to do the voting now than it's not 100 users any more, so I guess am using this site selfishly. Also, after 2 years here, I don't care about karma and post whatever I feel (that relates to the topic.). I used to spend the entire hour editing a post, but now I just come to read. Then again, I have to do homework and readings for 7 CS/Math classes this semester, so I am not here so much to say something about some random science topic. On the other hand, this site is great for opening up my mind and feeling like I'm part of a bigger and insightful nerd world. There are more submissions but much less startup advice that I haven't heard before, compared to when this was Startup News. On the other hand l, it is that breadth that I like while I'm in college. Any such stories with a high score, interesting title, or high number of comments I make sure to save to read later by upvoting (see /saved?id= feature). (I didn't save or upvote this article because it's neither science nor start up.)