I simply refuse to pay for a bot to upvote my content. I use the upvotes and comments that I receive as a form of analytics to see how well my content is doing overall and where I can improve. Buying votes merely skews that analytic factor away from accuracy and towards falsehood for the soul purpose of building reputation faster.
I don't even use a bot to curate my "Steemits Worth Mentioning" digest, that's all manually performed, which weeds out the risk of promoting someone that's just throwing out garbage. I really mean it when I said in one of my own previous posts that "I hate bots".