It is in deed an interesting topic to talk about @kevinwong. I believe that buying votes, if the content is high quality, is good in order to self-promote. If the content is bad, then this is a bad practice to do.
The final promotion of Steemit as a social platform are the articles. Basically every time we post, we are _throwing_ into the web a "piece" of Steemit. This post will give other people, a glimpse about the content within Steemit.
Unless Steemit may find a better way to reward new users, buying votes is a good strategy in order to stand out. Maybe it could be controlled a bit somehow by filtering good and bad content.

PS: I do support buying votes while publishing valuable content. I do not support buying votes for comments, just for posts. Also, I do not like that much the advertising of each voting seller.