Well people spam comments on high valued posts in the assumption they might attract big votes too, usually thinking the user with a high valued post is a whale of some sort.
We've seen how some users have bought large upvotes for low quality or plagiarized posts only to get them flagged hard. Sometimes even high quality content gets flagged as some are annoyed by the bought votes - even when the user themselves do not buy the votes but someone buys votes for them.
But buying votes for other people has mostly ended nowadays compared to the times when randowhale was the only voting bot and the votes sold were small.
I can admit when I'm selling my votes I'm not doing it to help any small accounts. It's purely to get my VP to use for some monetary gain. I'm not upvoting my own content and I'm normally trying to help other users with my votes even without being paid, but when I'm not doing that I'm picking the easy way for some money.
Currently the vote selling/buying is according to some one of the larger threats for Steem ecosystem. Luckily we are not blindly allowing any content getting large rewards with bought votes, as users are getting flagged for disagreement on rewards.
RE: Lets talk steemit #11 | Do you buy votes and why? An open conversation