I have used upvote bots in the past and really didn't think they helped my visibility. Many people like them and use them to get noticed. The idea is to break even or slightly ahead on the upvote investment. Any other people voting as a result of getting on the hot page will be a bonus. I have a different philosophy which is to not use them and blog more often to get the visibility. The number of blogs really help my following numbers.

Resteem bots can be useful, but each one has a different following and I haven't experimented with them.