It is about the STEEM POWER. your steempower is the voting power. the more steempower the more pennies per vote/comment/blog. In the background it is a bit more complicated. if you change look at yourself at https://steemd.com/@pocketechange you will see a entry on the Top right side VESTS this is the powernumber for the amount of beans you can spill per vote. It is calculated mainly from your STEEMPOWER and REPUTATION score.

the reputation score you can also see on steemd.com its on the left column down scroll a little bit you will see that you have a reputaion score of 355,574,735,52.
the more reputation the more followers, upvotes, trailvotes, $$.

You asked me how I can upvote someones comment the moment he wrote it. Good question! I delegate votingpower to very good people on steemit because i trust them, like @goodkarma, @curie, @thecryptofiend @ats-david, @robinhoodwhale, @minnowsupport, @steemtrail, @instructor2121, @pappa-pepper, @kevinwong . . . . . they are voting for me in my name and with my votingpower because I trust them. You wrote: I rarely upvote . . . . Thats a big mistake. Not voting, curating posting Is like a bitcoin miningfarm who gets only electricity for 45 minutes a day. I think this is a good comparison. mining on Steemit is upvoting, taking part in the action.

I hope this answers some of your questions!