"Someone has already made reference to the Mechanical Turk HIT under the answer in question. And the answer has been “collapsed” because of the policy violation, which means that no matter how many upvotes it receives paid or unpaid it won’t show up. Repeat offenders of Quora policy are warned and then potentially blocked."

And now to get rid of competitors, just open Mechanical Turk HITs to upvote their answers, report them, and watch them getting banned.