im wondering the same thing. im pretty sure you dont "lose" steem for upvoting, its just a charge that runs out if you vote to much or use to much. my votes are worth 0.01SBD right now, and sometimes i see that it is actually worth .01 and sometimes it comes up at .00, and usually that is when i upvote quite a few peoples stuff. i think you gain more steem power and voting weight the more upvotes you recieve? if thats not right at all please someone let me know, every article i read is pretty darn confusing haha