@exyle,
I wish to write a strategy behind vote bots! I assure you it's not very profitable! Because, most of vote bots are cheating the customer by showing high ROIs, but when we do the right calculation the end result is just a loss. Personally I am using vote bots sometimes, but it depends on the time that I am using the bot!
As you said, if STEEM went up it made a nice profit and vice versa can be happened as well!
Great thing to discuss about this topic!

Cheers~